Nouns denoting animals

abalone: any of various large edible marine gastropods of the genus Haliotis having an ear-shaped shell with pearly interior
Aberdeen Angus: black hornless breed from Scotland
abomasum: the fourth compartment of the stomach of a ruminant; the one where digestion takes place
abortus: a human fetus whose weight is less than 0.5 kilogram when removed or expelled from the mother's body
abrocome: ratlike rodent with soft fur and large ears of the Andes
Abudefduf saxatilis: large blue-grey black-striped damselfish; nearly worldwide
Abyssinian cat: a small slender short-haired breed of African origin having brownish fur with a reddish undercoat
Acanthisitta chloris: small green-and-bronze bird
acanthocephalan: any of various worms living parasitically in intestines of vertebrates having a retractile proboscis covered with many hooked spines
Acanthocybium solandri: large fast-moving predacious food and game fish; found worldwide
Acanthophis antarcticus: venomous Australian snake resembling an adder
acanthopterygian: a teleost fish with fins that are supported by sharp inflexible rays
Acanthoscelides obtectus: larvae live in and feed on growing or stored beans
Acanthurus chirurgus: surgeon fish of the West Indies
acarid: very small free-living arachnid that is parasitic on animals or plants; related to ticks
acarine: mite or tick
accentor: small sparrow-like songbird of mountainous regions of Eurasia
Accipiter cooperii: bluish-grey North American hawk having a darting flight
Accipiter gentilis: large hawk of Eurasia and North America used in falconry
Accipiter nisus: small hawk of Eurasia and northern Africa
Acherontia atropos: European hawkmoth with markings on the back resembling a human skull
Acheta assimilis: common American black cricket; attacks crops and also enters dwellings
Achoerodus gouldii: found around the Great Barrier Reef
acidophil: an organism that thrives in a relatively acid environment
Acinonyx jubatus: long-legged spotted cat of Africa and southwestern Asia having nonretractile claws; the swiftest mammal; can be trained to run down game
Acipenser huso: valuable source of caviar and isinglass; found in Black and Caspian seas
Acipenser transmontanus: food and game fish of marine and fresh waters of northwestern coast of North America
acridid: grasshopper with short antennae
Acridotheres tristis: dark brown crested bird of southeastern Asia
Acris crepitans: a cricket frog of eastern and central United States
Acris gryllus: a cricket frog of eastern United States
Acrocephalus schoenobaenus: small European warbler that breeds among reeds and wedges and winters in Africa
acrodont: an animal having teeth consolidated with the summit of the alveolar ridge without sockets
Actias luna: large pale-green American moth with long-tailed hind wings and a yellow crescent-shaped mark on each forewing
actinia: any sea anemone or related animal
actinomyces: soil-inhabiting saprophytes and disease-producing plant and animal parasites
actinomycete: any bacteria (some of which are pathogenic for humans and animals) belonging to the order Actinomycetales
actinomyxidian: parasites of worms
actinopod: protozoa having stiff rodlike radiating pseudopods
actinozoan: sessile marine coelenterates including solitary and colonial polyps; the medusoid phase is entirely suppressed
Actitis macularia: common North American sandpiper
aculea: small spiny outgrowth on the wings of certain insects
aculeus: a sharp-pointed process especially a sting of a hymenopterous insect
Adalia bipunctata: red ladybug with a black spot on each wing
Adapid group: extinct small mostly diurnal lower primates that fed on leaves and fruit; abundant in North America and Europe 30 to 50 million years ago; their descendents probably include the lemurs; some authorities consider them ancestral to anthropoids but others consider them only cousins
Addax nasomaculatus: large antelope with lightly spiraled horns of desert regions of northern Africa
Adelges abietis: a variety of adelgid
Adelges piceae: a variety of adelgid
adelgid: any of various insects that feed and form galls on conifers
Adenota vardoni: an African antelope closely related to the waterbuck
adenovirus: any of a group of viruses including those that in humans cause upper respiratory infections or infectious pinkeye
admiral: any of several brightly colored butterflies
adult: any mature animal
Aedes aegypti: mosquito that transmits yellow fever and dengue
Aegina: small medusa
Aegypius monachus: of southern Eurasia and northern Africa
Aegyptopithecus: extinct primate of about 38 million years ago; fossils found in Egypt
Aepyceros melampus: African antelope with ridged curved horns; moves with enormous leaps
aepyornis: huge (to 9 ft.) extinct flightless bird of Madagascar
Aerobacter aerogenes: a species of Gram-negative aerobic bacteria that produce gas and acid from sugars and are sometimes involved in the souring of milk
aerobe: an organism (especially a bacterium) that requires air or free oxygen for life
Aetobatus narinari: ray with back covered with white or yellow spots; widely distributed in warm seas
affenpinscher: European breed of small dog resembling a terrier with dark wiry hair and a tufted muzzle
Affirmed: thoroughbred that won the triple crown in 1978
Afghan hound: tall graceful breed of hound with a long silky coat; native to the Near East
African clawed frog: a tongueless frog native to Africa; established in the United States as result of release of laboratory and aquarium animals
African hunting dog: a powerful doglike mammal of southern and eastern Africa that hunts in large packs; now rare in settled area
African wild ass: a wild ass of Africa
Africander: tall large-horned humped cattle of South Africa; used for meat or draft
Afropavo congensis: both sexes are brightly colored
aftershaft: a supplementary feather (usually small) on the underside of the base of the shaft of some feathers in some birds
agama: small terrestrial lizard of warm regions of the Old World
agamid: a lizard of the family Agamidae
Agelaius phoeniceus: North American blackbird with scarlet patches on the wings
Agkistrodon contortrix: common coppery brown pit viper of upland eastern United States
Agkistrodon piscivorus: venomous semiaquatic snake of swamps in southern United States
agnathan: eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms
Agonus cataphractus: northern Atlantic sea poacher
Agriocharis ocellata: wild turkey of Central America and northern South America
Agrobacterium tumefaciens: the bacteria that produce crown gall disease in plants
Ailuropoda melanoleuca: large black-and-white herbivorous mammal of bamboo forests of China and Tibet; in some classifications considered a member of the bear family or of a separate family Ailuropodidae
Ailurus fulgens: reddish-brown Old World raccoon-like carnivore; in some classifications considered unrelated to the giant pandas
air bladder: an air-filled sac near the spinal column in many fishes that helps maintain buoyancy
air sac: any of the membranous air-filled extensions of the lungs of birds
air sac: any of the thin-walled extensions of the tracheae of insects
Airedale terrier: breed of large wiry-coated terrier bred in Yorkshire
Aix galericulata: showy crested Asiatic duck; often domesticated
Aix sponsa: showy North American duck that nests in hollow trees
Ajaia ajaja: tropical rose-colored New World spoonbill
ala: a wing of an insect
Alaskan malamute: breed of sled dog developed in Alaska
Alauda arvensis: brown-speckled European lark noted for singing while hovering at a great height
albatross: large web-footed birds of the southern hemisphere having long narrow wings; noted for powerful gliding flight
Albula vulpes: slender silvery marine fish found in tropical mud flats and mangrove lagoons
Alca torda: black-and-white northern Atlantic auk having a compressed sharp-edged bill
Alces alces: large northern deer with enormous flattened antlers in the male; called `elk' in Europe and `moose' in North America
Alectis ciliaris: fish having greatly elongated front rays on dorsal and anal fins
Alectoris graeca: of mountainous areas of southern Europe
Alectoris ruffa: common western European partridge with red legs
Alectura lathami: black megapode of wooded regions of Australia and New Guinea
alga: primitive chlorophyll-containing mainly aquatic eukaryotic organisms lacking true stems and roots and leaves
Algeripithecus minutus: tiny (150 to 300 grams) extinct primate of 46 to 50 million years ago; fossils found in Algeria; considered by some authorities the leading candidate for the first anthropoid
allantois: the vascular fetal membrane that lies below the chorion and develops from the hindgut in many embryonic higher vertebrates (reptiles, birds and mammals)
alley cat: a homeless cat
alligator lizard: slim short-limbed lizard having a distinctive fold on each side that permits expansion; of western North America
Alligator mississipiensis: large alligator of the southeastern United States
Alligator sinensis: small alligator of the Yangtze valley of China having unwebbed digits
alligator: either of two amphibious reptiles related to crocodiles but with shorter broader snouts
allosaur: late Jurassic carnivorous dinosaur; similar to but somewhat smaller than tyrannosaurus
Alopex lagopus: thickly-furred fox of Arctic regions; brownish in summer and white in winter
Alopius vulpinus: large pelagic shark of warm seas with a whiplike tail used to round up small fish on which to feed
Alosa alosa: European shad
Alosa chrysocloris: shad that spawns in streams of the Mississippi drainage; very similar to Alosa sapidissima
alphavirus: an arbovirus of the family Togaviridae that can cause a variety of encephalitis in horses
Alsophila pometaria: North American moth with grey-winged males and wingless females; larvae are fall cankerworms
alula: tuft of small stiff feathers on the first digit of a bird's wing
alula: scalelike structure between the base of the wing and the halter of a two-winged fly
Alytes cisternasi: similar in habit to Alytes obstetricians
Alytes obstetricans: European toad whose male carries the fertilized eggs wrapped around its hind legs until they hatch
amadavat: red Asian weaverbirds often kept as cage birds
amazon: mainly green tropical American parrots
amberfish: any of several amber to coppery fork-tailed warm-water carangid fishes
Ambloplites rupestris: game and food fish of upper Mississippi and Great Lakes
Amblyrhynchus cristatus: shore-dwelling seaweed-eating lizard of the Galapagos Islands
ambulacrum: one of the five areas on the undersurface of an echinoderm on which the tube feet are located
Ambystoma maculatum: glossy black North American salamander with yellow spots
Ambystoma mexicanum: larval salamander of mountain lakes of Mexico that usually lives without metamorphosing
Ambystoma talpoideum: brownish-black burrowing salamander of southeastern United States
Ambystoma tigrinum: widely distributed brown or black North American salamander with vertical yellowish blotches
ambystomid: small to moderate-sized terrestrial or semiaquatic New World salamander
ameba: naked freshwater or marine or parasitic protozoa that form temporary pseudopods for feeding and locomotion
Ameiurus Melas: catfish common in eastern United States
American badger: a variety of badger native to America
American buffalo: large shaggy-haired brown bison of North American plains
American crayfish: common large crayfishes of eastern North America
American egret: a common egret of the genus Egretta found in America; it is a variety of the Old World white egret Casmerodius albus
American flying squirrel: New World flying squirrels
American foxhound: an American breed of foxhounds used for hunting both in packs and individually
American green toad: small green or yellow-green toad with small black bars and stripes
American harvest mouse: any of several small greyish New World mice inhabiting e.g. grain fields
American mastodont: mastodon of North America; in some classifications considered a mammoth rather than a mastodon
American saddle horse: a high-stepping horse originating in Kentucky
American smooth dogfish: found along the Atlantic coast of the Americas
American Staffordshire terrier: American breed of muscular terriers with a short close-lying stiff coat
American water ouzel: a water ouzel of western North America
American water shrew: water shrew of North America
American water spaniel: breed of medium-sized spaniels originating in America having chocolate or liver-colored curly coat
American widgeon: a widgeon the male of which has a white crown
American woodcock: small long-billed woodcock; prized as a game bird
amethystine python: a python having the color of amethyst
Amia calva: primitive long-bodied carnivorous freshwater fish with a very long dorsal fin; found in sluggish waters of North America
Ammotragus lervia: wild sheep of northern Africa
amnion: thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
Amniota: higher vertebrates (reptiles, birds and mammals) possessing an amnion during development
amniote: any member of the Amniota
amphibian: cold-blooded vertebrate typically living on land but breeding in water; aquatic larvae undergo metamorphosis into adult form
amphibian family: any family of amphibians
amphibian genus: any genus of amphibians
amphidiploid: (genetics) an organism or cell having a diploid set of chromosomes from each parent
amphioxus: small translucent lancet-shaped burrowing marine animal; primitive forerunner of the vertebrates
amphipod: a kind of malacostracan crustacean
Amphiprion percula: an anemone fish of the genus Amphiprion
amphiuma: aquatic eel-shaped salamander having two pairs of very small feet; of still muddy waters in the southern United States
Anabas testudineus: a small perch of India whose gills are modified to allow it to breathe air; has spiny pectoral fins that enable it to travel on land
Anabrus simplex: large dark wingless cricket-like katydid of arid parts of western United States
anaerobe: an organism (especially a bacterium) that does not require air or free oxygen to live
anapsid: primitive reptile having no opening in the temporal region of the skull; all extinct except turtles
Anas acuta: long-necked river duck of the Old and New Worlds having elongated central tail feathers
Anas clypeata: freshwater duck of the northern hemisphere having a broad flat bill
Anas crecca: common teal of Eurasia and North America
Anas discors: American teal
Anas penelope: freshwater duck of Eurasia and northern Africa related to mallards and teals
Anas platyrhynchos: wild dabbling duck from which domestic ducks are descended; widely distributed
Anas querquedula: small Eurasian teal
Anas rubripes: a dusky duck of northeastern United States and Canada
Anasa tristis: large black American bug that sucks sap of vines of the gourd family
anaspid: extinct small freshwater jawless fish usually having a heterocercal tail and an armored head; of the Silurian and Devonian
anatotitan: one of the largest and most famous duck-billed dinosaurs
anchovy: small herring-like plankton-eating fishes often canned whole or as paste; abundant in tropical waters worldwide
Ancylus fluviatilis: minute conical gastropod superficially resembling a limpet but living and feeding on freshwater plants
andrena: a bee that is a member of the genus Andrena
Aneides lugubris: yellow-spotted brown salamander of California woodlands
anemone fish: live associated with sea anemones
anemone: marine polyps that resemble flowers but have oral rings of tentacles; differ from corals in forming no hard skeleton
angelfish: a butterfly fish of the genus Pomacanthus
anglewing: nymphalid butterfly having angular notches on the outer edges of the forewings
angleworm: terrestrial worm that burrows into and helps aerate soil; often surfaces when the ground is cool or wet; used as bait by anglers
Angora cat: a long-haired breed of cat similar to the Persian cat
Angora goat: a domestic breed of goat raised for its long silky hair which is the true mohair
Angora rabbit: domestic breed of rabbit with long white silky hair
anguid lizard: any of a small family of lizards widely distributed in warm areas; all are harmless and useful as destroyers of e.g. slugs and insects
Anguilla sucklandii: New Zealand eel
Anguillula aceti: minute eelworm that feeds on organisms that cause fermentation in e.g. vinegar
Anguis fragilis: small burrowing legless European lizard with tiny eyes; popularly believed to be blind
Anhima cornuta: screamer having a hornlike process projecting from the forehead
Anhinga anhinga: blackish New World snakebird of swampy regions
anhinga: fish-eating bird of warm inland waters having a long flexible neck and slender sharp-pointed bill
ani: black tropical American cuckoo
animal foot: the pedal extremity of vertebrates other than human beings
animal leg: the leg of an animal
animal order: the order of animals
animal virus: an animal pathogen that is a virus
animalcule: microscopic organism such as an amoeba or paramecium
Anisotremus surinamensis: dusky grey food fish found from Louisiana and Florida southward
Anisotremus virginicus: black and gold grunt found from Bermuda to Caribbean to Brazil
ankylosaur: having the back covered with thick bony plates; thought to have walked with a sprawling gait resembling a lizard's
annelid: worms with cylindrical bodies segmented both internally and externally
Anoa depressicornis: small buffalo of the Celebes having small straight horns
Anolis carolinensis: small arboreal tropical American insectivorous lizards with the ability to change skin color
Anomala orientalis: introduced into United States from the Orient; larvae feed on roots of sugarcane and other grasses
anomalops: fish having a luminous organ beneath eye; of warm waters of the western Pacific and Puerto Rico
Anomalopteryx oweni: the smallest moa; slender moa about the size of a large turkey
Anomia ephippium: thin-shelled bivalve having the right valve deeply notched
anopheline: any mosquito of the genus Anopheles
Anoplophora glabripennis: a beetle from China that has been found in the United States and is a threat to hardwood trees; lives inside the tree; no natural predators in the United States
Anser anser: common grey wild goose of Europe; ancestor of many domestic breeds
Anser cygnoides: very large wild goose of northeast Asia; interbreeds freely with the greylag
anseriform bird: chiefly web-footed swimming birds
ant bird: any of various dull-colored South American birds that feeding on ants some following army ant swarms
ant cow: excretes a honeylike substance eaten by ants
ant lion: winged insect resembling a dragonfly; the larvae (doodlebugs) dig conical pits where they wait to catch e.g. ants
ant lion: the larva of any of several insects
ant shrike: antbirds superficially resembling shrikes
ant thrush: a kind of antbird
ant: social insect living in organized colonies; characteristically the males and fertile queen have wings during breeding season; wingless sterile females are the workers
anteater: a burrowing monotreme mammal covered with spines and having a long snout and claws for hunting ants and termites; native to New Guinea
anteater: a burrowing monotreme mammal covered with spines and having a long snout and claws for hunting ants and termites; native to Australia
anteater: toothless mammal of southern Africa and Asia having a body covered with horny scales and a long snout for feeding on ants and termites
antelope: graceful Old World ruminant with long legs and horns directed upward and backward; includes gazelles; springboks; impalas; addax; gerenuks; blackbucks; dik-diks
antenna: one of a pair of mobile appendages on the head of e.g. insects and crustaceans; typically sensitive to touch and taste
Antheraea mylitta: oriental moth that produces brownish silk
Antheraea pernyi: a Chinese moth that produces a brownish silk
Antheraea polyphemus: very large yellowish-brown American silkworm moth with large eyespots on hind wings; larvae feed on fruit and shade trees
Anthonomus grandis: greyish weevil that lays its eggs in cotton bolls destroying the cotton
Anthrenus scrophulariae: a small black and red and white carpet beetle
anthropoid: any member of the suborder Anthropoidea including monkeys and apes and hominids
anthropoid ape: any tailless ape of the families Pongidae and Hylobatidae
Anthus pratensis: a common pipit that is brown above and white below; widely distributed in northern and central Europe and in Asia
Antidorcas marsupialis: a South African gazelle noted for springing lightly into the air
Antilocapra americana: fleet antelope-like ruminant of western North American plains with small branched horns
Antilope cervicapra: common Indian antelope with a dark back and spiral horns
antler: deciduous horn of a member of the deer family
Antrozous pallidus: drab yellowish big-eared bat that lives in caves
anuran: any of various tailless stout-bodied amphibians with long hind limbs for leaping; semiaquatic and terrestrial species
Aotus trivirgatus: nocturnal monkey of Central America and South America with large eyes and thick fur
Apatosaurus excelsus: huge quadrupedal herbivorous dinosaur common in North America in the late Jurassic
Apatura iris: large European butterfly the male of which has wings shaded with purple
ape: any of various primates with short tails or no tail at all
aphid: any of various small plant-sucking insects
aphid lion: carnivorous larva of lacewing flies
Aphis fabae: blackish aphid that infests e.g. beans and sugar beets
Aphis pomi: bright green aphid; feeds on and causes curling of apple leaves
Aphriza virgata: sandpiper-like shorebird of Pacific coasts of North America and South America
Aphrophora saratogensis: feeds on pines in northern United States
Apis mellifera: social bee often domesticated for the honey it produces
Apis mellifera scutellata: a strain of bees that originated in Brazil in the 1950s as a cross between an aggressive African bee and a honeybee; retains most of the traits of the African bee; now spread as far north as Texas
aplacophoran: deep-water wormlike mollusks lacking calcareous plates on the body but having fine slimy spicules on the covering mantle
Aplodontia rufa: bulky nocturnal burrowing rodent of uplands of the Pacific coast of North America; the most primitive living rodent
Aplysia punctata: naked marine gastropod having a soft body with reduced internal shell and two pairs of ear-like tentacles
apodeme: ridge-like ingrowth of the exoskeleton of an arthropod that supports internal organs and provides attachment points for muscles
apodiform bird: nonpasserine bird having long wings and weak feet; spends much of its time in flight
Apogon maculatus: a cardinalfish found in tropical Atlantic coastal waters
apolemia: large siphonophore of up to 50 ft long
Appaloosa: a hardy breed of saddle horse developed in western North America and characteristically having a spotted rump
appendicularia: free-swimming tadpole-shaped pelagic tunicate resembling larvae of other tunicates
Appenzeller: a smaller of the four Swiss breeds
Aptenodytes forsteri: the largest penguin; an Antarctic penguin
Aptenodytes patagonica: large penguin on islands bordering the Antarctic Circle
apteryx: nocturnal flightless bird of New Zealand having a long neck and stout legs; only surviving representative of the order Apterygiformes
aquatic bird: wading and swimming and diving birds of either fresh or salt water
aquatic mammal: whales and dolphins; manatees and dugongs; walruses; seals
aquatic vertebrate: animal living wholly or chiefly in or on water
Aquila chrysaetos: large eagle of mountainous regions of the northern hemisphere having a golden-brown head and neck
Aquila rapax: brownish eagle of Africa and parts of Asia
Arabian: a spirited graceful and intelligent riding horse native to Arabia
arachnid: air-breathing arthropods characterized by simple eyes and four pairs of legs
arame: an edible seaweed with a mild flavor
Aramus guarauna: wading bird of South America and Central America
Aramus pictus: wading bird of Florida, Cuba and Jamaica having a drooping bill and a distinctive wailing call
Aranea diademata: a spider common in European gardens
Araneus cavaticus: an orange and tan spider with darkly banded legs that spins an orb web daily
arborvirus: a large heterogeneous group of RNA viruses divisible into groups on the basis of the virions; they have been recovered from arthropods, bats, and rodents; most are borne by arthropods; they are linked by the epidemiologic concept of transmission between vertebrate hosts by arthropod vectors (mosquitoes, ticks, sandflies, midges, etc.) that feed on blood; they can cause mild fevers, hepatitis, hemorrhagic fever, and encephalitis
arcella: an amoeba-like protozoan with a chitinous shell resembling an umbrella
archaebacteria: considered ancient life forms that evolved separately from bacteria and blue-green algae
Archaeopteryx lithographica: extinct primitive toothed bird of the Jurassic period having a long feathered tail and hollow bones; usually considered the most primitive of all birds
archaeornis: extinct primitive toothed bird with a long feathered tail and three free clawed digits on each wing
archenteron: central cavity of the gastrula; becomes the intestinal or digestive cavity
archiannelid: small primitive marine worm lacking external segmentation and resembling polychaete larvae
Archidiskidon imperator: largest known mammoth; of America
Archilochus colubris: a kind of hummingbird
architeuthis: largest mollusk known about but never seen (to 60 feet long)
Archosargus probatocephalus: large (up to 20 lbs) food fish of the eastern coast of the United States and Mexico
Archosargus rhomboidalis: sea bream of warm Atlantic waters
archosaur: extinct reptiles including: dinosaurs; plesiosaurs; pterosaurs; ichthyosaurs; thecodonts
Arctic ground squirrel: large ground squirrel of the North American far north
Arctictis bintourong: arboreal civet of Asia having a long prehensile tail and shaggy black hair
arctiid: stout-bodied broad-winged moth with conspicuously striped or spotted wings; larvae are hairy caterpillars
Arctocebus calabarensis: a kind of lemur
Arctocephalus philippi: a fur seal of the Pacific coast of California and southward
Arctonyx collaris: southeast Asian badger with a snout like a pig
Ardea herodius: large American heron having bluish-grey plumage
Ardea occidentalis: large white heron of Florida and the Florida Keys
Arenaria interpres: common Arctic turnstone that winters in South America and Australia
Arenaria-Melanocephala: common turnstone of the Pacific coast of North America
Arenaviridae: a family of arborviruses carried by arthropods
arenavirus: animal viruses belonging to the family Arenaviridae
argasid: tick lacking a dorsal shield and having mouth parts on the under side of the head
argentine: any of various small silver-scaled salmon-like marine fishes
argentinosaur: huge herbivorous dinosaur of Cretaceous found in Argentina
Argiope aurantia: a widely distributed North American garden spider
Argonauta argo: cephalopod mollusk of warm seas whose females have delicate papery spiral shells
argus: large brilliantly patterned East Indian pheasant
Argyrotaenia citrana: California moth whose larvae live in especially oranges
Arilus cristatus: large predatory North American bug that sucks the blood of other insects
arista: bristlelike process near the tip of the antenna of certain flies
Arizona elegans: nocturnal burrowing snake of western United States with shiny tan scales
ark shell: marine bivalve mollusk having a heavy toothed shell with a deep boat-like inner surface
Arkansas kingbird: a kingbird seen in western United States; head and back are pale grey and the breast is yellowish and the tail is black
armadillo: burrowing chiefly nocturnal mammal with body covered with strong horny plates
armor: tough more-or-less rigid protective covering of an animal or plant
armored catfish: South American catfish having the body covered with bony plates
armored dinosaur: dinosaurs having bony armour
armored scale: insect having a firm covering of wax especially in the female
army ant: tropical nomadic ant that preys mainly on other insects
armyworm: larva of fungus gnat that feed on cereals and other grains; they march in large companies in regular order when the food is exhausted
arrowworm: any worm of the Chaetognatha; transparent marine worm with horizontal lateral and caudal fins and a row of movable curved spines at each side of the mouth
Artemia salina: common to saline lakes
arthropod: invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin
arthropod family: any of the arthropods
arthropod genus: a genus of arthropods
artiodactyl: placental mammal having hooves with an even number of functional toes on each foot
Arvicola amphibius: common large Eurasian vole
Ascaphus trui: western North American frog with a taillike copulatory organ
Ascaridia galli: intestinal parasite of domestic fowl
Ascaris lumbricoides: intestinal parasite of humans and pigs
ascidian: minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leaves
ascidian tadpole: free-swimming larva of ascidians; they have a tail like a tadpole that contains the notochord
Ascophyllum nodosum: similar to and found with black rockweed
Asian coral snake: of India
Asian horseshoe crab: horseshoe crab of the coast of eastern Asia
Asian tiger mosquito: striped native of Japan thriving in southwestern and midwestern United States and spreading to the Caribbean; potential carrier of serious diseases
Asian wild ox: genus of Asiatic wild oxen
Asiatic flying squirrel: nocturnal rodent of Asia having furry folds of skin between forelegs and hind legs enabling it to move by gliding leaps
Asio otus: slender European owl of coniferous forests with long ear tufts
Aspidelaps lubricus: small widely distributed arboreal snake of southern Africa banded in black and orange
Aspidiotus perniciosus: small east Asian insect naturalized in the United States that damages fruit trees
Aspidophoroides monopterygius: small very elongate sea poachers
ass: hardy and sure-footed animal smaller and with longer ears than the horse
assassin bug: a true bug: long-legged predacious bug living mostly on other insects; a few suck blood of mammals
Assault: thoroughbred that won the triple crown in 1946
Astrophyton muricatum: a variety of basket star
Astropogon stellatus: found in West Indies; lives in mantle cavity of a living conch
Ateles geoffroyi: arboreal monkey of tropical America with long slender legs and long prehensile tail
Athene noctua: small European owl
Atherinopsis californiensis: a relatively large silversides of the Pacific coast of North America (known to reach 18 inches in length)
Atlantic bonito: medium-sized tuna-like food fish of warm Atlantic and Pacific waters; less valued than tuna
Atlantic bottlenose dolphin: the most common dolphin of northern Atlantic and Mediterranean; often kept captive and trained to perform
Atlantic salmon: found in northern coastal Atlantic waters or tributaries; adults do not die after spawning
Atlantic spiny dogfish: destructive dogfish of the Atlantic coastal waters of America and Europe; widely used in anatomy classes
attack dog: a watchdog trained to attack on command
Atticus atlas: giant saturniid moth widespread in Asia; sometimes cultured for silk
auk: black-and-white short-necked web-footed diving bird of northern seas
auklet: any of several small auks of the northern Pacific coasts
Aulostomus maculatus: tropical Atlantic fish with a long snout; swims snout down
Auriparus flaviceps: very small yellow-headed titmouse of western North America
Australian bonytongue: a species of large fish found in Australian rivers
Australian magpie: black-and-white oscine birds that resemble magpies
Australian sea lion: a variety of sea lion found in Australia
Australian stilt: long-legged three-toed wading bird of brackish marshes of Australia
Australian terrier: small greyish wire-haired breed of terrier from Australia similar to the cairn
Australian turtledove: small Australian dove
australopithecine: any of several extinct humanlike bipedal primates with relatively small brains of the genus Australopithecus; from 1 to 4 million years ago
Australopithecus afarensis: fossils found in Ethiopia; from 3.5 to 4 million years ago
Australopithecus africanus: gracile hominid of southern Africa; from about 3 million years ago
Australopithecus boisei: large-toothed hominid of eastern Africa; from 1 to 2 million years ago
Australopithecus robustus: large-toothed hominid of southern Africa; from 1.5 to 2 million years ago; formerly Paranthropus
Automeris io: large yellow American moth having a large eyelike spot on each hind wing; the larvae have stinging spines
Avahi laniger: nocturnal indris with thick grey-brown fur and a long tail
avocet: long-legged web-footed black-and-white shorebird with slender upward-curving bill
Ayrshire: hardy breed of dairy cattle from Ayr, Scotland
Aythya affinis: common scaup of North America; males have purplish heads
Aythya americana: North American diving duck with a grey-and-black body and reddish-brown head
Aythya ferina: heavy-bodied Old World diving duck having a grey-and-black body and reddish head
Aythya marila: large scaup of North America having a greenish iridescence on the head of the male
Aythya valisineria: North American wild duck valued for sport and food
B: aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil
baa-lamb: child's word for a sheep or lamb
babbler: any of various insectivorous Old World birds with a loud incessant song; in some classifications considered members of the family Muscicapidae
baboon: large terrestrial monkeys having doglike muzzles
baby: a very young mammal
baby bird: young bird not yet fledged
Babyrousa Babyrussa: Indonesian wild pig with enormous curved canine teeth
Bacillus anthracis: a species of bacillus that causes anthrax in humans and in animals (cattle and swine and sheep and rabbits and mice and guinea pigs); can be used a bioweapon
Bacillus subtilis: a species of bacillus found in soil and decomposing organic matter; some strains produce antibiotics
bacteria family: a family of bacteria
bacteria genus: a genus of bacteria
bacteria order: an order of bacteria
bacteria species: a species of bacteria
bacteria: (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants
bacteriochlorophyll: a substance in photosensitive bacteria that is related to but different from chlorophyll of higher plants
bacteriophage: a virus that is parasitic (reproduces itself) in bacteria
bacteroid: a rodlike bacterium (especially any of the rod-shaped or branched bacteria in the root nodules of nitrogen-fixing plants)
badger: sturdy carnivorous burrowing mammal with strong claws; widely distributed in the northern hemisphere
badger dog: small long-bodied short-legged German breed of dog having a short sleek coat and long drooping ears; suited for following game into burrows
bag: mammary gland of bovids (cows and sheep and goats)
Baiomys taylori: very small dark greyish brown mouse resembling a house mouse; of Texas and Mexico
Bairdiella chrysoura: small silvery drumfish often mistaken for white perch; found along coasts of United States from New York to Mexico
Balaena mysticetus: large-mouthed Arctic whale
Balaeniceps rex: large stork-like bird of the valley of the White Nile with a broad bill suggesting a wooden shoe
Balaenoptera acutorostrata: small finback of coastal waters of Atlantic and Pacific
Balaenoptera borealis: similar to but smaller than the finback whale
Balaenoptera musculus: largest mammal ever known; bluish-grey migratory whalebone whale mostly of southern hemisphere
Balaenoptera physalus: large flat-headed whalebone whale having deep furrows along the throat; of Atlantic and Pacific
balancer: either of the rudimentary hind wings of dipterous insects; used for maintaining equilibrium during flight
Balanus balanoides: barnacle that attaches to rocks especially in intertidal zones
baleen whale: whale with plates of whalebone along the upper jaw for filtering plankton from the water
Balistes vetula: tropical Atlantic fish
banana quit: any of several honeycreepers
banded gecko: any of several geckos with dark bands across the body and differing from typical geckos in having movable eyelids; of United States southwest and Florida Gulf Coast
bandicoot: any of various agile ratlike terrestrial marsupials of Australia and adjacent islands; insectivorous and herbivorous
bandicoot rat: burrowing scaly-tailed rat of India and Ceylon
bangtail: a horse bred for racing
Bankia setaceae: giant shipworm of the Pacific coast of North America
bantam: any of various small breeds of fowl
barb: one of the parallel filaments projecting from the main shaft of a feather
barbel: slender tactile process on the jaws of a fish
barbet: small brightly colored stout-billed tropical bird having short weak wings
bark beetle: small beetle that bores tunnels in the bark and wood of trees; related to weevils
bark louse: any of several insects living on the bark of plants
barker: informal terms for dogs
barking deer: small Asian deer with small antlers and a cry like a bark
barnacle: marine crustaceans with feathery food-catching appendages; free-swimming as larvae; as adults form a hard shell and live attached to submerged surfaces
barosaur: a dinosaur that could grow to be as tall as a building five stories tall
barracouta: a large marine food fish common on the coasts of Australia, New Zealand, and southern Africa
barracuda: any voracious marine fish of the genus Sphyraena having an elongated cylindrical body and large mouth with projecting lower jaw and long strong teeth
Bartramian sandpiper: large plover-like sandpiper of North American fields and uplands
basenji: small smooth-haired breed of African origin having a tightly curled tail and the inability to bark
basilisk: small crested arboreal lizard able to run on its hind legs; of tropical America
basket fish: any starfish-like animal of the genera Euryale or Astrophyton or Gorgonocephalus having slender complexly branched interlacing arms radiating from a central disc
bass: nontechnical name for any of numerous edible marine and freshwater spiny-finned fishes
Bassariscus astutus: raccoon-like omnivorous mammal of Mexico and the southwestern United States having a long bushy tail with black and white rings
basset: smooth-haired breed of hound with short legs and long ears
bat: nocturnal mouselike mammal with forelimbs modified to form membranous wings and anatomical adaptations for echolocation by which they navigate
batfish: bottom-dweller of warm western Atlantic coastal waters having a flattened scaleless body that crawls about on fleshy pectoral and pelvic fins
bay: a horse of a moderate reddish-brown color
beach flea: small amphipod crustaceans that hop like fleas; common on ocean beaches
beagle: a small short-legged smooth-coated breed of hound
beak: beaklike mouth of animals other than birds (e.g., turtles)
beak: horny projecting mouth of a bird
beaked whale: any of several whales inhabiting all oceans and having beaklike jaws with vestigial teeth in the upper jaw
bear: massive plantigrade carnivorous or omnivorous mammals with long shaggy coats and strong claws
bear claw: claw of a bear; often used in jewelry
bear cub: a young bear
beard: hairy growth on or near the face of certain mammals
beard worm: slender animal with tentacles and a tubelike outer covering; lives on the deep ocean bottom
beard: tuft of strong filaments by which e.g. a mussel makes itself fast to a fixed surface
beast of burden: an animal such as a donkey or ox or elephant used for transporting loads or doing other heavy work
beaver: large semiaquatic rodent with webbed hind feet and a broad flat tail; construct complex dams and underwater lodges
beaver rat: amphibious rat of Australia and New Guinea
Bedlington terrier: a light terrier groomed to resemble a lamb
bee: any of numerous hairy-bodied insects including social and solitary species
bee beetle: European beetle; infests beehives
bee eater: colorful chiefly tropical Old World bird having a strong graceful flight; feeds on especially bees
bee fly: hairy nectar-eating fly that resembles a bee; larvae are parasitic on larvae of bees and related insects
bee killer: swift predatory fly having a strong body like a bee with the proboscis hardened for sucking juices of other insects captured on the wing
beef: cattle that are reared for their meat
beefalo: hardy breed of cattle resulting from crossing domestic cattle with the American buffalo; yields leaner beef than conventional breeds
beetle: insect having biting mouthparts and front wings modified to form horny covers overlying the membranous rear wings
belemnite: a conical calcareous fossil tapering to a point at one end and with a conical cavity at the other end containing (when unbroken) a small chambered phragmocone from the shell of any of numerous extinct cephalopods of the family Belemnitidae
Belgian hare: red breed of domestic rabbits; hybrid between Old World rabbit and hare
Belgian shepherd: hardy working dog developed in Belgium for herding sheep
bell magpie: bluish black fruit-eating bird with a bell-like call
bellbird: any of several tropical American birds of the genus Procnias having a bell-like call
bellows fish: small bottom-dwelling fish of warm seas having a compressed body and a long snout with a toothless mouth
bellwether: sheep that leads the herd often wearing a bell
belly: the underpart of the body of certain vertebrates such as snakes or fish
Bemisia tabaci: a strain of pest accidentally imported into Florida from the Middle East then spread to California where it is a very serious pest feeding on almost all vegetable crops and poinsettias
Bengal tiger: southern short-haired tiger
Bernese mountain dog: large powerful long-haired black-coated Swiss dog with deep tan or russet markings on legs and white blaze and feet and chest marking; formerly used for draft
beroe: delicately iridescent thimble-shaped ctenophores
bettong: short-nosed rat kangaroo
Bibos frontalis: ox of southeast Asia sometimes considered a domesticated breed of the gaur
Bibos gaurus: wild ox of mountainous areas of eastern India
biddy: young bird especially of domestic fowl
biddy: adult female chicken
big bedbug: large bloodsucking bug
big cat: any of several large cats typically able to roar and living in the wild
big game: large animals that are hunted for sport
bigeye: red fishes of American coastal tropical waters having very large eyes and rough scales
billfish: giant warm-water game fish having a prolonged and rounded toothless upper jaw
billfish: elongate European surface-dwelling predacious fishes with long toothed jaws; abundant in coastal waters
billy: male goat
biped: an animal with two feet
biplane flying fish: having both pectoral and pelvic fins enlarged
bird: warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings
bird dog: a gun dog trained to locate or retrieve birds
bird family: a family of warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings
bird genus: a genus of birds
bird louse: wingless insect with mouth parts adapted for biting; mostly parasitic on birds
bird of Jove: any of various large keen-sighted diurnal birds of prey noted for their broad wings and strong soaring flight
bird of Juno: very large terrestrial southeast Asian pheasant often raised as an ornamental bird
bird of Minerva: nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes
bird of paradise: any of numerous brilliantly colored plumed birds of the New Guinea area
bird of passage: any bird that migrates seasonally
bird of prey: any of numerous carnivorous birds that hunt and kill other animals
bird's foot: the foot of a bird
bird-footed dinosaur: any of numerous carnivorous dinosaurs of the Triassic to Cretaceous with short forelimbs that walked or ran on strong hind legs
bison: any of several large humped bovids having shaggy manes and large heads and short horns
Bison bonasus: European bison having a smaller and higher head than the North American bison
bitch: female of any member of the dog family
biting midge: minute two-winged insect that sucks the blood of mammals and birds and other insects
Bitis arietans: large African viper that inflates its body when alarmed
Bitis gabonica: large heavy-bodied brilliantly marked and extremely venomous west African viper
bittern: relatively small compact tawny-brown heron with nocturnal habits and a booming cry; found in marshes
bivalve: marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged together
black bass: widely distributed and highly prized American freshwater game fishes (sunfish family)
black carpet beetle: a carpet beetle that is solid black in color
black cock: male black grouse
black fly: small blackish stout-bodied biting fly having aquatic larvae; sucks the blood of birds as well as humans and other mammals
black fox: red fox in the color phase when its pelt is mostly black
black grouse: grouse of which the male is bluish-black
black sheep: sheep with a black coat
black squirrel: fox squirrel or grey squirrel in the black color phase
black-and-tan coonhound: American breed of large powerful hound dogs used for hunting raccoons and other game
black-headed snake: small secretive ground-living snake; found from central United States to Argentina
Blackburnian warbler: black-and-white North American wood warbler having an orange-and-black head and throat
blackfish: female salmon that has recently spawned
bladder worm: encysted saclike larva of the tapeworm
blanquillo: important marine food fishes
Blarina brevicauda: North American shrew with tail less than half its body length
blastocele: the fluid-filled cavity inside a blastula
blastocyst: the blastula of a placental mammal in which some differentiation of cells has occurred
blastoderm: a layer of cells on the inside of the blastula
blastomere: any cell resulting from cleavage of a fertilized egg
blastopore: the opening into the archenteron
blastosphere: early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs
Blatta orientalis: dark brown cockroach originally from orient now nearly cosmopolitan in distribution
Blattella germanica: small light-brown cockroach brought to United States from Europe; a common household pest
Blenheim spaniel: red-and-white variety of English toy spaniel
blennioid: elongated mostly scaleless marine fishes with large pectoral fins and reduced pelvic fins
Blennius pholis: European scaleless blenny
blenny: small usually scaleless fishes with comb-like teeth living about rocky shores; are territorial and live in holes between rocks
blind snake: wormlike burrowing snake of warm regions having vestigial eyes
blindworm: any of the small slender limbless burrowing wormlike amphibians of the order Gymnophiona; inhabit moist soil in tropical regions
Blissus leucopterus: small black-and-white insect that feeds on cereal grasses
blister beetle: beetle that produces a secretion that blisters the skin
blood clam: red-blooded clam
blood fluke: flatworms parasitic in the blood vessels of mammals
bloodhound: a breed of large powerful hound of European origin having very acute smell and used in tracking
bloodsucker: carnivorous or bloodsucking aquatic or terrestrial worms typically having a sucker at each end
bloodworm: a segmented marine worm with bright red body; often used for bait
blow fly: large usually hairy metallic blue or green fly; lays eggs in carrion or dung or wounds
blower: large aquatic carnivorous mammal with fin-like forelimbs no hind limbs, including: whales; dolphins; porpoises; narwhals
blowfish: any of numerous marine fishes whose elongated spiny body can inflate itself with water or air to form a globe; several species contain a potent nerve poison; closely related to spiny puffers
blue: any of numerous small butterflies of the family Lycaenidae
blue cat: a large catfish of the Mississippi valley
blue fox: a variety of Arctic fox having a pale grey winter coat
blue point Siamese: Siamese cat having a bluish cream-colored body and dark grey points
blue point: small edible oyster typically from the southern shore of Long Island
blue-green algae: predominantly photosynthetic prokaryotic organisms containing a blue pigment in addition to chlorophyll; occur singly or in colonies in diverse habitats; important as phytoplankton
bluebill: diving ducks of North America having a bluish-grey bill
bluebird: blue North American songbird
bluebird: fruit-eating mostly brilliant blue songbird of the East Indies
bluetick: a very fast American hound; white mottled with bluish grey
boa: any of several chiefly tropical constrictors with vestigial hind limbs
boar: an uncastrated male hog
boarfish: fish with large eyes and long snouts
boarhound: large hound used in hunting wild boars
boat bug: carnivorous aquatic bug having paddle-like hind legs
boatswain bird: mostly white web-footed tropical seabird often found far from land
bob: a short or shortened tail of certain animals
bobwhite: a popular North American game bird; named for its call
bollworm: any of various moth caterpillars that destroy cotton bolls
bombardier beetle: beetle that ejects audibly a pungent vapor when disturbed
Bombina bombina: toad of central and eastern Europe having red or orange patches mixed with black on its underside
bombycid: moderate-sized Asiatic moth whose larvae feed on mulberry leaves and produce silk
Bombycilla: waxwings
Bombycilla cedrorun: widely distributed over temperate North America
Bombycilla garrulus: large waxwing of northern North America; similar to but larger than the cedar waxwing
Bombyx mori: stocky creamy-white Asiatic moth found almost entirely under human care; the source of most of the silk commerce
Bonasa umbellus: valued as a game bird in eastern United States and Canada
bone-headed dinosaur: bipedal herbivorous dinosaurs with bony crowns
bonito: any of various scombroid fishes intermediate in size and characteristics between mackerels and tunas
bonxie: gull-like jaeger of northern seas
bony fish: any fish of the class Osteichthyes
booby: small tropical gannet having a bright bill or bright feet or both
Border collie: developed in the area between Scotland and England usually having a black coat with white on the head and tip of tail used for herding both sheep and cattle
Border terrier: small rough-coated terrier of British origin
borer: any of various insects or larvae or mollusks that bore into wood
borrelia: cause of e.g. European and African relapsing fever
Bos banteng: wild ox of the Malay Archipelago
Bos grunniens: large long-haired wild ox of Tibet often domesticated
Bos indicus: any of several breeds of Indian cattle; especially a large American heat and tick resistant greyish humped breed evolved in the Gulf States by interbreeding Indian cattle and now used chiefly for crossbreeding
Bos primigenius: large recently extinct long-horned European wild ox; considered one of the ancestors of domestic cattle
Bos taurus: domesticated bovine animals as a group regardless of sex or age
Boselaphus tragocamelus: large Indian antelope; male is blue-grey with white markings; female is brownish with no horns
Boskop man: possible early Homo sapiens represented by a cranium found in the Transvaal; formerly considered a separate species
Boston terrier: small pug-faced American terrier breed having a smooth brindle or black coat with white markings
bot: botfly larva; typically develops inside the body of a horse or sheep or human
Botaurus lentiginosus: a kind of bittern
Botaurus stellaris: a kind of bittern
botfly: stout-bodied hairy dipterous fly whose larvae are parasites on humans and other mammals
Bothrops atrops: large extremely venomous pit viper of Central America and South America
bottlenose: any of several dolphins with rounded forehead and well-developed beak; chiefly of northern Atlantic and Mediterranean
bottom fish: fish that live on the sea bottom (particularly the commercially important gadoid fish like cod and haddock, or flatfish like flounder)
bottom lurkers: a fish that lurks on the bottom of a body of water
bottom-dweller: a fish that lives and feeds on the bottom of a body of water
bottom-feeder: a scavenger that feeds low on the food chain
Bouviers des Flandres: rough-coated breed used originally in Belgium for herding and guarding cattle
bovid: hollow-horned ruminants
bovine: any of various members of the genus Bos
bowerbird: any of various birds of the Australian region whose males build ornamented structures resembling bowers in order to attract females
box tortoise: chiefly terrestrial turtle of North America; shell can be closed tightly
boxer: a breed of stocky medium-sized short-haired dog with a brindled coat and square-jawed muzzle developed in Germany
boxfish: any of numerous small tropical fishes having body and head encased in bony plates
Brabancon griffon: a variety of Brussels griffon having a short smooth coat
brachiopod: marine animal with bivalve shell having a pair of arms bearing tentacles for capturing food; found worldwide
brachyuran: typical crabs
bracketed blenny: small eellike fishes common in shallow waters of the northern Atlantic
Bradypus tridactylus: a sloth that has three long claws on each forefoot and each hindfoot
brain coral: massive reef-building coral having a convoluted and furrowed surface
Brama raii: deep-bodied sooty-black pelagic spiny-finned fish of the northern Atlantic and northern Pacific; valued for food
branchia: respiratory organ of aquatic animals that breathe oxygen dissolved in water
branchial arch: one of the bony or cartilaginous arches on each side of the pharynx that support the gills of fishes and aquatic amphibians
branchial cleft: one of a series of slit openings in the pharynxes of fishes and aquatic amphibians through which water passes
branchiopod: aquatic crustaceans typically having a carapace and many pairs of leaflike appendages used for swimming as well as respiration and feeding
brant: small dark geese that breed in the north and migrate southward
Branta bernicla: the best known variety of brant goose
Branta canadensis: common greyish-brown wild goose of North America with a loud, trumpeting call
Branta leucopsis: European goose smaller than the brant; breeds in the far north
Brazilian trumpeter: trumpeter of Brazil and Guiana; often kept to protect poultry in Brazil
bream: any of various usually edible freshwater percoid fishes having compressed bodies and shiny scales; especially (but not exclusively) of the genus Lepomis
bream: any of numerous marine percoid fishes especially (but not exclusively) of the family Sparidae
breast: the part of an animal's body that corresponds to a person's chest
Brevoortia tyrannis: shad-like North American marine fishes used for fish meal and oil and fertilizer
briard: old French breed of large strong usually black dogs having a long tail and long wavy and slightly stiff coat
bristle: a stiff hair
bristletail: small wingless insect with a long bristlelike tail
brit: the young of a herring or sprat or similar fish
brit: minute crustaceans forming food for right whales
Brittany spaniel: tall active short-tailed French breed of bird dog having a usually smooth orange- or liver-and-white coat
brittle star: an animal resembling a starfish with fragile whiplike arms radiating from a small central disc
broadbill: small birds of the Old World tropics having bright plumage and short wide bills
broadtail: hardy coarse-haired sheep of central Asia; lambs are valued for their soft curly black fur
brocket: male red deer in its second year
brocket: small South American deer with unbranched antlers
bronc: an unbroken or imperfectly broken mustang
brood bitch: a bitch used for breeding
brood hen: a domestic hen ready to brood
broodmare: a female horse used for breeding
Brosme brosme: large edible marine fish of northern coastal waters; related to cod
brotula: deep-sea fishes
brown algae: algae having the chlorophyll masked by brown and yellow pigments
brown bat: any of numerous medium to small insectivorous bats found worldwide in caves and trees and buildings
brown bullhead: freshwater catfish of eastern United States
brown lacewing: small dark-colored lacewing fly
Brown Swiss: large hardy brown breed of dairy cattle from Switzerland
Brucella: an aerobic Gram-negative coccobacillus that causes brucellosis; can be used as a bioweapon
Bruchus pisorum: larvae live in and feed on seeds of the pea plant
bruin: a conventional name for a bear used in tales following usage in the old epic `Reynard the Fox'
brush: a bushy tail or part of a bushy tail (especially of the fox)
brush kangaroo: any of various small or medium-sized kangaroos; often brightly colored
brush-footed butterfly: medium to large butterflies found worldwide typically having brightly colored wings and much-reduced nonfunctional forelegs carried folded on the breast
brush-tail porcupine: porcupine with a tuft of large beaded bristles on the tail
Brussels griffon: breed of various very small compact wiry-coated dogs of Belgian origin having a short bearded muzzle
bryozoan: sessile aquatic animal forming mossy colonies of small polyps each having a curved or circular ridge bearing tentacles; attach to stones or seaweed and reproduce by budding
Bubalus bubalis: an Asian buffalo that is often domesticated for use as a draft animal
Bubalus mindorensis: small buffalo of Mindoro in the Philippines
bubble shell: marine gastropod mollusk having a very small thin shell
Bubo virginianus: brown North American horned owl
Bubulcus ibis: small white egret widely distributed in warm regions often found around grazing animals
Bucephala islandica: North American goldeneye diving duck
Bucephela albeola: small North American diving duck; males have bushy head plumage
Bucephela clangula: large-headed swift-flying diving duck of Arctic regions
buck: mature male of various mammals (especially deer or antelope)
bucking bronco: a wild horse that is vicious and difficult or impossible to break in
buckskin: horse of a light yellowish dun color with dark mane and tail
Budorcas taxicolor: large heavily built goat antelope of eastern Himalayan area
buffalo fish: any of several large suckers of the Mississippi valley
bufo: any toad of the genus Bufo
Bufo americanus: common toad of America
Bufo boreas: of a great variety of habitats from southern Alaska to Baja California west of the Rockies
Bufo calamita: common brownish-yellow short-legged toad of western Europe; runs rather than hops
Bufo marinus: largest known toad species; native to Central America; valuable destroyer of insect pests
Bufo microscaphus: a uniformly warty stocky toad of washes and streams of semiarid southwestern United States
Bufo speciosus: nocturnal burrowing toad of mesquite woodland and prairies of the United States southwest
bug: general term for any insect or similar creeping or crawling invertebrate
bug: a minute life form (especially a disease-causing bacterium); the term is not in technical use
bug: insects with sucking mouthparts and forewings thickened and leathery at the base; usually show incomplete metamorphosis
bulbul: nightingale spoken of in Persian poetry
bull: mature male of various mammals of which the female is called `cow'; e.g. whales or elephants or especially cattle
bull: uncastrated adult male of domestic cattle
bull mastiff: large powerful breed developed by crossing the bulldog and the mastiff
bull snake: any of several large harmless rodent-eating North American burrowing snakes
bull terrier: a powerful short-haired terrier originated in England by crossing the bulldog with terriers
bullbat: mainly nocturnal North American goatsucker
bulldog ant: any of the large fierce Australian ants of the genus Myrmecia
bullhead: freshwater sculpin with a large flattened bony-plated head with hornlike spines
bullhead: any of several common freshwater catfishes of the United States
bullock: young bull
bullock: castrated bull
bumblebee: robust hairy social bee of temperate regions
Bungarus fasciatus: sluggish krait banded with black and yellow
bunny: (usually informal) especially a young rabbit
bunting: any of numerous seed-eating songbirds of Europe or North America
Bunyaviridae: a large family of arboviruses that affect a wide range of hosts (mainly vertebrates and arthropods)
bunyavirus: an animal virus belonging to the family Bunyaviridae; can be used as a bioweapon
Burchell's zebra: of the plains of central and eastern Africa
Burhinus oedicnemus: large-headed large-eyed crepuscular or nocturnal shorebird of the Old World and tropical America having a thickened knee joint
Burmeisteria retusa: of southern South America
Burmese cat: a short-haired breed with body similar to the Siamese cat but having a solid dark brown or grey coat
burrfish: any of several fishes having rigid flattened spines
burro: small donkey used as a pack animal
bush baby: agile long-tailed nocturnal African lemur with dense woolly fur and large eyes and ears
bush shrike: an African shrike
bush tit: active grey titmice of western North America
bustard: large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes
bustard quail: small quail-like terrestrial bird of southern Eurasia and northern Africa that lacks a hind toe; classified with wading birds but inhabits grassy plains
butcherbird: large carnivorous Australian bird with the shrike-like habit of impaling prey on thorns
butcherbird: shrikes that impale their prey on thorns
Buteo buteo: the common European short-winged hawk
Buteo jamaicensis: dark brown American hawk species having a reddish-brown tail
Buteo lagopus: large hawk of the northern hemisphere that feeds chiefly on small rodents and is beneficial to farmers
Buteo lineatus: North American hawk with reddish brown shoulders
buteonine: any hawk of the genus Buteo
butterfish: small marine fish with a short compressed body and feeble spines
butterfly: diurnal insect typically having a slender body with knobbed antennae and broad colorful wings
butterfly fish: small usually brilliantly colored tropical marine fishes having narrow deep bodies with large broad fins; found worldwide
butterfly ray: a stingray with a short tail and a broad fin
butterflyfish: tropical fish with huge fanlike pectoral fins for underwater gliding; unrelated to searobins
bycatch: unwanted marine creatures that are caught in the nets while fishing for another species
Cabassous unicinctus: naked-tailed armadillo of tropical South America
cabbage butterfly: white butterfly whose larvae (cabbageworms) feed on cabbage
cacique: black-and-red or black-and-yellow orioles of the American tropics
cackler: a hen that has just laid an egg and emits a shrill squawk
cactus wren: large harsh-voiced American wren of arid regions of the United States southwest and Mexico
caddice fly: small moth-like insect having two pairs of hairy membranous wings and aquatic larvae
caddisworm: larva of the caddis fly; constructs a case of silk covered with sand or plant debris
Cadra cautella: a moth whose larvae feed on and mat together with webbing various stored products of vegetable origin
Cadra figulilella: moth whose larvae attack dried fruits and cereal products
caiman lizard: crocodile-like lizard of South America having powerful jaws for crushing snails and mussels
Caiman sclerops: caiman with bony ridges about the eyes; found from southern Mexico to Argentina
caiman: a semiaquatic reptile of Central and South America that resembles an alligator but has a more heavily armored belly
Cairina moschata: large crested wild duck of Central America and South America; widely domesticated
cairn: small rough-haired breed of terrier from Scotland
Calamus penna: from Florida and Bahamas to Brazil
calamus: the hollow spine of a feather
calf: young of domestic cattle
calf: young of various large placental mammals e.g. whale or giraffe or elephant or buffalo
calico cat: a cat having black and cream-colored and yellowish markings
caliculus: a small cup-shaped structure (as a taste bud or optic cup or cavity of a coral containing a polyp)
Calidris canutus: a sandpiper that breeds in the Arctic and winters in the southern hemisphere
Calidris Ferruginea: Old World sandpiper with a curved bill like a curlew
Calidris melanotos: American sandpiper that inflates its chest when courting
California newt: newt that is similar to Taricha granulosa in characteristics and habitat
Callimorpha jacobeae: large red-and-black European moth; larvae feed on leaves of ragwort; introduced into United States to control ragwort
Callinectes sapidus: bluish edible crab of Atlantic and Gulf Coasts of North America
Calliphora vicina: blowfly with iridescent blue body; makes a loud buzzing noise in flight
Callisaurus draconoides: swift lizard with long black-banded tail and long legs; of deserts of United States and Mexico
Callorhinus ursinus: of Pacific coast from Alaska southward to California
calosoma: any beetle of the genus Calosoma
Calosoma scrutator: large metallic blue-green beetle that preys on caterpillars; found in North America
Calymmatobacterium granulomatis: the species of bacteria that causes granuloma inguinale
camel: cud-chewing mammal used as a draft or saddle animal in desert regions
Camelus bactrianus: two-humped camel of the cold deserts of central Asia
Camelus dromedarius: one-humped camel of the hot deserts of northern Africa and southwestern Asia
Campephilus principalis: large black-and-white woodpecker of southern United States and Cuba having an ivory bill; nearly extinct
Canachites canadensis: North American grouse that feeds on evergreen buds and needles
canary: any of several small Old World finches
Cancer borealis: large red deep-water crab of the eastern coast of North America
Cancer irroratus: crab of eastern coast of North America
Cancer magister: small edible crab of Pacific coast of North America
canid: any of various fissiped mammals with nonretractile claws and typically long muzzles
Canis aureus: Old World nocturnal canine mammal closely related to the dog; smaller than a wolf; sometimes hunts in a pack but usually singly or as a member of a pair
Canis dingo: wolflike yellowish-brown wild dog of Australia
Canis familiaris: a member of the genus Canis (probably descended from the common wolf) that has been domesticated by man since prehistoric times; occurs in many breeds
Canis latrans: small wolf native to western North America
Canis lupus: a wolf with a brindled grey coat living in forested northern regions of North America
Canis lupus tundrarum: wolf of Arctic North America having white fur and a black-tipped tail
Canis rufus: reddish-grey wolf of southwestern North America
cankerworm: green caterpillar of a geometrid moth; pest of various fruit and shade trees
cannon bone: greatly developed metatarsal or metacarpal bone in the shank or cannon part of the leg in hoofed mammals
cannon: lower part of the leg extending from the hock to the fetlock in hoofed mammals
capelan: very small northern fish; forage for sea birds and marine mammals and other fishes
capon: castrated male chicken
Capra aegagrus: wild goat of Iran and adjacent regions
Capra falconeri: large Himalayan goat with large spiraled horns
Capra hircus: any of various breeds of goat raised for milk or meat or wool
Capra ibex: wild goat of mountain areas of Eurasia and northern Africa having large recurved horns
Capreolus capreolus: small graceful deer of Eurasian woodlands having small forked antlers
caprimulgid: mainly crepuscular or nocturnal nonpasserine birds with mottled greyish-brown plumage and large eyes; feed on insects
caprimulgiform bird: long-winged nonpasserine birds
Caprimulgus carolinensis: large whippoorwill-like bird of the southern United States
Caprimulgus europaeus: Old World goatsucker
Caprimulgus vociferus: American nocturnal goatsucker with grey-and-white plumage
caprine animal: any of numerous agile ruminants related to sheep but having a beard and straight horns
Capros aper: fish with a projecting snout
capsid: the outer covering of protein surrounding the nucleic acid of a virus
capsid: a variety of leaf bug
carabao: water buffalo of the Philippines
carabid beetle: predacious shining black or metallic terrestrial beetle that destroys many injurious insects
caracara: any of various long-legged carrion-eating hawks of South America and Central America
carangid: a percoid fish of the family Carangidae
Caranx bartholomaei: fish of western Atlantic and Gulf of Mexico
Caranx crysos: fish of western Atlantic: Cape Cod to Brazil
Caranx hippos: fish of western Atlantic and Gulf of Mexico
carapace: hard outer covering or case of certain organisms such as arthropods and turtles
Carassius auratus: small golden or orange-red freshwater fishes of Eurasia used as pond or aquarium fishes
Carassius carassius: European carp closely resembling wild goldfish
carcase: the dead body of an animal especially one slaughtered and dressed for food
Carcharhinus leucas: a most common shark in temperate and tropical coastal waters worldwide; heavy-bodied and dangerous
Carcharhinus limbatus: widely distributed shallow-water shark with fins seemingly dipped in ink
Carcharhinus obscurus: relatively slender blue-grey shark; nearly worldwide in tropical and temperate waters
Carcharhinus plumbeus: most common grey shark along coasts of middle Atlantic states; sluggish and occasionally caught by fishermen
Carcharinus longimanus: large deep-water shark with white-tipped dorsal fin; worldwide distribution; most dangerous shark
Carcharodon carcharias: large aggressive shark widespread in warm seas; known to attack humans
Cardigan Welsh corgi: slightly bowlegged variety of corgi having rounded ears and a long tail
cardinalfish: small red fishes of coral reefs and inshore tropical waters
Cardium edule: common edible European cockle
Carduelis cannabina: small Old World finch whose male has a red breast and forehead
Carduelis carduelis: small European finch having a crimson face and yellow-and-black wings
Carduelis cucullata: South American species of scarlet finch with black head and wings and tail
Carduelis flammea: small siskin-like finch with a red crown and a rosy breast and rump
Carduelis hornemanni: small siskin-like finch with a red crown
Carduelis spinus: small yellow-and-black Eurasian finch with a sharp beak
Caretta caretta: very large carnivorous sea turtle; wide-ranging in warm open seas
Cariama cristata: Brazilian Cariama; sole representative of the genus Cariama
caribe: small voraciously carnivorous freshwater fishes of South America that attack and destroy living animals
carinate: birds having keeled breastbones for attachment of flight muscles
Carniolan bee: greyish highly productive European honeybee that has a quiet disposition
carnivore: any animal that feeds on flesh
carnivore: a terrestrial or aquatic flesh-eating mammal
carnivorous bat: typically having large ears and feeding primarily on insects; worldwide in distribution
carnosaur: large carnivorous bipedal dinosaur having huge claws
carp: any of various freshwater fish of the family Cyprinidae
carpenter ant: ant that nests in decaying wood in which it bores tunnels for depositing eggs
carpenter bee: large solitary bee that lays eggs in tunnels bored into wood or plant stems
carpet beetle: small beetle whose larvae are household pests feeding on woolen fabrics
Carphophis amoenus: small reddish wormlike snake of eastern United States
Carpocapsa pomonella: a small grey moth whose larvae live in apples and English walnuts
Carpodacus mexicanus: small finch originally of the western United States and Mexico
Carpodacus purpureus: North American finch having a raspberry-red head and breast and rump
carriage dog: a large breed having a smooth white coat with black or brown spots; originated in Dalmatia
carrier: (genetics) an organism that possesses a recessive gene whose effect is masked by a dominant allele; the associated trait is not apparent but can be passed on to offspring
carrier pigeon: a homing pigeon used to carry messages
carrion: the dead and rotting body of an animal; unfit for human food
cart horse: draft horse kept for pulling carts
cartilaginous fish: fishes in which the skeleton may be calcified but not ossified
caseworm: insect larva that constructs a protective case around its body
Cashmere goat: Himalayan goat having a silky undercoat highly prized as cashmere wool
Casmerodius albus: widely distributed Old World white egret
cassowary: large black flightless bird of Australia and New Guinea having a horny head crest
Castor canadensis: a variety of beaver found in almost all areas of North America except Florida
cat shark: small bottom-dwelling sharks with cat-like eyes; found along continental slopes
cat: feline mammal usually having thick soft fur and no ability to roar: domestic cats; wildcats
catamount: short-tailed wildcats with usually tufted ears; valued for their fur
caterpillar: a wormlike and often brightly colored and hairy or spiny larva of a butterfly or moth
catfish: any of numerous mostly freshwater bottom-living fishes of Eurasia and North America with barbels like whiskers around the mouth
catfish: large ferocious northern deep-sea food fishes with strong teeth and no pelvic fins
Catharacta skua: large brown skua of the northern Atlantic
Cathartes aura: a New World vulture that is common in South America and Central America and the southern United States
Catocala nupta: moth having dull forewings and red-marked hind wings
Catoptrophorus semipalmatus: large North American shorebird of eastern and Gulf Coasts
catostomid: a cypriniform fish of the family Catostomidae
caudal appendage: tail especially of a mammal posterior to and above the anus
caudal fin: the tail of fishes and some other aquatic vertebrates
caudate: amphibians that resemble lizards
cavalry horse: horse trained for battle
Cavia cobaya: stout-bodied nearly tailless domesticated cavy; often kept as a pet and widely used in research
Cavia porcellus: South American cavy; possibly ancestral to the domestic guinea pig
cavy: short-tailed rough-haired South American rodent
Cebuella pygmaea: the smallest monkey; of tropical forests of the Amazon
Cebus capucinus: monkey of Central America and South America having thick hair on the head that resembles a monk's cowl
centipede: chiefly nocturnal predacious arthropod having a flattened body of 15 to 173 segments each with a pair of legs, the foremost pair being modified as prehensors
centrarchid: small carnivorous freshwater percoid fishes of North America usually having a laterally compressed body and metallic luster: crappies; black bass; bluegills; pumpkinseed
Centrocercus urophasianus: large grouse of sagebrush regions of North America
Centropistes striata: bluish black-striped sea bass of the Atlantic coast of the United States
Centropristis philadelphica: a kind of sea bass
Centropus phasianinus: Australian bird with a tail like a pheasant
Centropus sinensis: common coucal of India and China
cephalaspid: extinct jawless fish of the Devonian with armored head
cephalochordate: fish-like animals having a notochord rather than a true spinal column
cephalopod: marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles
Cephalopterus ornatus: black tropical American bird having a large overhanging crest and long feathered wattle
Cepphus columba: northern Pacific guillemot
Cepphus grylle: northern Atlantic guillemot
Cerapteryx graminis: European moth with white antler-like markings on the forewings; the larvae damage pastures and grasslands
ceras: one of the often brightly colored and branching hornlike structures on the back of the nudibranch (and other related mollusks) that serve as gills
Cerastes cornutus: highly venomous viper of northern Africa and southwestern Asia having a horny spine above each eye
ceratodus: extinct lungfish
ceratopsian: any of several four-footed herbivorous dinosaurs with enormous beaked skulls; of the late Cretaceous in North America and Mongolia
ceratosaur: primitive medium-sized theropod; swift-running bipedal carnivorous dinosaur having grasping hands with sharp claws and a short horn between the nostrils; Jurassic in North America
Ceratotherium simum: large light-grey African rhinoceros having two horns; endangered; sometimes placed in genus Diceros
cercaria: tadpole-shaped parasitic larva of a trematode worm; tail disappears in adult stage
Cercopithecus aethiops: white and olive green East African monkey with long white tufts of hair beside the face
Cercopithecus aethiops pygerythrus: South African monkey with black face and hands
Cercopithecus aethiops sabaeus: common savannah monkey with greenish-grey back and yellow tail
Cercopithecus talapoin: smallest guenon monkey; of swampy central and west African forests
cere: the fleshy, waxy covering at the base of the upper beak of some birds
Certhia americana: a common creeper in North America with a down-curved bill
Certhia familiaris: common European brown-and-buff tree creeper with down-curved bill
cervid: distinguished from Bovidae by the male's having solid deciduous antlers
Cervus elaphus: common deer of temperate Europe and Asia
Cervus elaphus canadensis: large North American deer with large much-branched antlers in the male
Cervus unicolor: a deer of southern Asia with antlers that have three tines
Ceryle alcyon: greyish-blue North American kingfisher with a chestnut band on its chest
cestode: ribbonlike flatworms that are parasitic in the intestines of humans and other vertebrates
Cetonia aurata: a common metallic green European beetle: larvae feed on plant roots and adults on leaves and flowers of e.g. roses
Cetorhinus maximus: large harmless plankton-eating northern shark; often swims slowly or floats at the sea surface
chachalaca: slender arboreal guan resembling a wild turkey; native to Central America and Mexico; highly regarded as game birds
Chaenopsis ocellata: found from Florida to Cuba
chaeta: a stiff chitinous seta or bristle especially of an annelid worm
Chaetodipterus faber: deep-bodied disk-shaped food fish of warmer western Atlantic coastal waters
chaetodon: any fish of the genus Chaetodon
chalaza: one of two spiral bands of tissue connecting the egg yolk to the enclosing membrane at either end of the shell
chalcid: any of various tiny insects whose larvae are parasites on eggs and larvae of other insects; many are beneficial in destroying injurious insects
chalcis fly: a variety of chalcid fly
Chamaea fasciata: small brown bird of California resembling a wren
Chamaeleo chamaeleon: a chameleon found in Africa
Chamaeleo oweni: a kind of chameleon
chamaeleon: lizard of Africa and Madagascar able to change skin color and having a projectile tongue
chambered nautilus: cephalopod of the Indian and Pacific oceans having a spiral shell with pale pearly partitions
chameleon tree frog: a form of tree toad
char: any of several small trout-like fish of the genus Salvelinus
characid: any freshwater fish of the family Characinidae
Charadrius melodus: small plover of eastern North America
Charadrius morinellus: rare plover of upland areas of Eurasia
Charadrius vociferus: American plover of inland waters and fields having a distinctive cry
charger: formerly a strong swift horse ridden into battle
Charina bottae: boa of grasslands and woodlands of western North America; looks and feels like rubber with tail and head of similar shape
Charolais: large white or cream-colored breed from France
Charronia flavigula: large yellow and black marten of southern China and Burma
Chateura pelagica: American swift that nests in e.g. unused chimneys
chatterer: passerine bird of New World tropics
Chauna torquata: largest crested screamer; native to southern Brazil and Argentina
chela: a grasping structure on the limb of a crustacean or other arthropods
chelicera: either of the first pair of fang-like appendages near the mouth of an arachnid; often modified for grasping and piercing
Chelifer cancroides: minute arachnid sometimes found in old papers
Chelonia mydas: large tropical turtle with greenish flesh used for turtle soup
chelonian: a reptile of the order Chelonia
Chelydra serpentina: large-headed turtle with powerful hooked jaws found in or near water; prone to bite
Chen caerulescens: North American wild goose having dark plumage in summer but white in winter
cherrystone: a half-grown quahog
Chesapeake Bay retriever: American breed having a short thick oily coat ranging from brown to light tan
chestnut: a dark golden-brown or reddish-brown horse
chestnut: a small horny callus on the inner surface of a horse's leg
Cheviot: hardy hornless sheep of the Cheviot Hills noted for its short thick wool
chevrotain: very small hornless deer-like ruminant of tropical Asia and west Africa
Chiacoan peccary: a recently discovered large wild pig of Paraguay
chickadee: any of various small grey-and-black songbirds of North America
chicken hawk: nontechnical term for any hawks said to prey on poultry
chicken snake: large North American snake
chigger: larval mite that sucks the blood of vertebrates including human beings causing intense irritation
Chihuahua: an old breed of tiny short-haired dog with protruding eyes from Mexico held to antedate Aztec civilization
Chihuahuan spotted whiptail: having longitudinal stripes overlaid with light spots; upland lizard of United States southwest and Mexico
Chilomeniscus cinctus: a sand snake of southwestern United States; lives in fine to coarse sand or loamy soil in which it `swims'; banding resembles that of coral snakes
chimaera: a deep-sea fish with a tapering body, smooth skin, and long threadlike tail
Chimaera monstrosa: large European chimaera
Chinchilla laniger: small rodent with soft pearly grey fur; native to the Andes but bred in captivity for fur
chine: backbone of an animal
Chinese paddlefish: fish of larger rivers of China similar to the Mississippi paddlefish
chipmunk: a burrowing ground squirrel of western America and Asia; has cheek pouches and a light and dark stripe running down the body
chiton: primitive elongated bilaterally symmetrical marine mollusk having a mantle covered with eight calcareous plates
Chlamydera nuchalis: large bowerbird of northern Australia
chlamydia: coccoid rickettsia infesting birds and mammals; cause infections of eyes and lungs and genitourinary tract
Chlamydia psittaci: bacteria responsible for the sexually transmitted disease chlamydia
Chlamydia trachomatis: bacteria responsible for the sexually transmitted diseases chlamydia and lymphogranuloma venereum
Chlamydosaurus kingi: large arboreal insectivorous Australian lizard with a ruff of skin around the neck
Chlamyphorus truncatus: very small Argentine armadillo with pale silky hair and pink plates on head and neck
chlorella: any alga of the genus Chlorella
chlorofucin: the chlorophyll present in brown algae, diatoms, and flagellates
Chlorophoneus nigrifrons: a kind of bush shrike
chlorophyl: any of a group of green pigments found in photosynthetic organisms; there are four naturally occurring forms
chlorophyll a: a blue-black plant pigment having a blue-green alcohol solution; found in all higher plants
chlorophyll b: a dark-green plant pigment having a brilliant green alcohol solution; generally characteristic of higher plants
chlorophyll d: the chlorophyll found (together with chlorophyll a) in red algae
chlorophyte: algae that are clear green in color; often growing on wet ricks or damp wood or the surface of stagnant water
Chlorura chlorura: towhee of the Rocky Mountains
choanocyte: any of the flagellated cells in sponges having a collar of cytoplasm around the flagellum; they maintain a flow of water through the body
Choeronycteris mexicana: small-eared Mexican bat with a long slender nose
Choloepus didactylus: relatively small fast-moving sloth with two long claws on each front foot
Choloepus hoffmanni: a sloth of Central America that has two long claws on each forefoot and three long claws on each hindfoot
Chondrus crispus: dark purple edible seaweed of the Atlantic coasts of Europe and North America
chordamesoderm: the area of mesoderm that forms the notochord
chordate: any animal of the phylum Chordata having a notochord or spinal column
chordate family: any family in the phylum Chordata
chordate genus: any genus in the phylum Chordata
chorioallantoic membrane: the very vascular fetal membrane composed of the fused chorion and adjacent wall of the allantois
chorion: the outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)
chorionic villus: one of the tiny villi that stick out of the fetal chorion and combine with the mother's uterine tissue to form the placenta
Choriotis australis: popular Australian game bird
Chorizagrotis auxiliaris: larvae (of a noctuid moth) that travel in large groups and destroy grains and alfalfa in the midwestern states
chorus frog: any of several small North American frogs having a loud call
chough: a European corvine bird of small or medium size with red legs and glossy black plumage
chow: breed of medium-sized dogs with a thick coat and fluffy curled tails and distinctive blue-black tongues; believed to have originated in northern China
Chronoperates paradoxus: shrew-sized protomammal from the Alberta region of Canada; from about 55 million years ago (much more recent than other mammal-like reptiles)
chrysalis: pupa of a moth or butterfly enclosed in a cocoon
Chrysaora quinquecirrha: a type of jellyfish
Chrysemys picta: freshwater turtles having bright yellow and red markings; common in the eastern United States
Chrysolophus pictus: brightly colored crested pheasant of mountains of western and central Asia
chrysomelid: brightly colored beetle that feeds on plant leaves; larvae infest roots and stems
Chrysophrys auratus: Australian food fish having a pinkish body with blue spots
Chrysophrys australis: important dark-colored edible food and game fish of Australia
chrysopid: pale green unpleasant-smelling lacewing fly having carnivorous larvae
Chunga burmeisteri: Argentinian Cariama
church mouse: a fictional mouse created by Lewis Carroll
cicada: stout-bodied insect with large membranous wings; male has drum-like organs for producing a high-pitched drone
cichlid: freshwater fishes of tropical America and Africa and Asia similar to American sunfishes; some are food fishes; many small ones are popular in aquariums
Ciconia ciconia: the common stork of Europe; white with black wing feathers and a red bill
Ciconia nigra: Old World stork that is glossy black above and white below
ciliate: a protozoan with a microscopic appendage extending from the surface of the cell
cilium: a hairlike projection from the surface of a cell; provides locomotion in free-swimming unicellular organisms
Cimex lectularius: bug of temperate regions that infests especially beds and feeds on human blood
cinnamon bear: reddish-brown color phase of the American black bear
Circus Aeruginosus: Old World harrier frequenting marshy regions
Circus cyaneus: common harrier of North America and Europe; nests in marshes and open land
cirrus: a slender flexible animal appendage as on barnacles or crinoids or many insects; often tactile
Cistothorus palustris: American wren that inhabits tall reed beds
Cistothorus platensis: small American wren inhabiting wet sedgy meadows
Citation: thoroughbred that won the triple crown in 1948
Citellus citellus: rather large central Eurasian ground squirrel
Citellus lateralis: common black-striped reddish-brown ground squirrel of western North America; resembles a large chipmunk
Citellus leucurus: small ground squirrel of western United States
Citellus variegatus: large grey ground squirrel of rocky areas of the southwestern United States
Citharichthys cornutus: a whiff found in waters from the Bahamas and northern Gulf of Mexico to Brazil
civet: cat-like mammal typically secreting musk used in perfumes
Cladorhyncus leucocephalum: web-footed Australian stilt with reddish-brown pectoral markings
clam: burrowing marine mollusk living on sand or mud; the shell closes with viselike firmness
clamshell: the shell of a clam
Clangula hyemalis: a common long-tailed sea duck of the northern parts of the United States
class Actinozoa: a large class of sedentary marine coelenterates that includes sea anemones and corals; the medusoid phase is entirely suppressed
class Amphibia: the class of vertebrates that live on land but breed in water; frogs; toads; newts; salamanders; caecilians
class Aphasmidia: one of two subgroups of Nematoda used in some classification systems
class Arachnida: a large class of arthropods including spiders and ticks and scorpions and daddy longlegs; have four pairs of walking legs and no wings
class Archiannelida: a class of Annelida
class Ascidiaceae: sometimes classified as an order: sea squirts
class Asteroidea: sea stars
class Aves: (ornithology) the class of birds
class Bacillariophyceae: marine and freshwater eukaryotic algae: diatoms
class Cephalopoda: octopuses; squids; cuttlefish; pearly nautilus
class Cestoda: tapeworms
class Channidae: snakeheads
class Charophyceae: in some classifications: contains only the order Charales
class Chilopoda: arthropods having the trunk composed of numerous somites each bearing one pair of legs: centipedes
class Chlorophyceae: algae distinguished chiefly by having flagella and a clear green color, their chlorophyll being masked little if at all by other pigments
class Chondrichthyes: cartilaginous fishes
class Chrysophyceae: all the yellow-green algae having flagella of unequal length
class Ciliophora: class of protozoa having cilia or hairlike appendages on part or all of the surface during some part of the life cycle
class Crinoidea: sea lilies
class Crustacea: class of mandibulate arthropods including: lobsters; crabs; shrimps; woodlice; barnacles; decapods; water fleas
class Cryptophyceae: motile usually brownish-green protozoa-like algae
class Cyanobacteria: photosynthetic bacteria found in fresh and salt water, having chlorophyll a and phycobilins; once thought to be algae: blue-green algae
class Cyclosporeae: in more recent classifications superseded by the order Fucales
class Echinoidea: sea urchins and sand dollars
class Euglenophyceae: coextensive with the division Euglenophyta
class Gasteropoda: snails and slugs and their relatives
class Hexapoda: insects; about five-sixths of all known animal species
class Hirudinea: hermaphroditic aquatic or terrestrial or parasitic annelids
class Holothuroidea: class of echinoderms including the sea cucumbers
class Hyalospongiae: sponges with siliceous spicules that have six rays; choanocytes are restricted to finger-shaped chambers
class Hydrozoa: coelenterates typically having alternation of generations; hydroid phase is usually colonial giving rise to the medusoid phase by budding: hydras and jellyfishes
class Lamellibranchia: oysters; clams; scallops; mussels
class Larvacea: small free-swimming tunicates; sometimes classified as an order
class Mammalia: warm-blooded vertebrates characterized by mammary glands in the female
class Mastigophora: protozoa having flagella
class Merostomata: used in some classifications; includes the orders Xiphosura and Eurypterida
class Myriapoda: arthropods having the body composed of numerous double somites each with two pairs of legs: millipedes
class Nuda: ctenophores lacking tentacles; comprises one genus: beroe
class Oligochaeta: earthworms
class Onychophora: enigmatic small elongated wormlike terrestrial invertebrates of damp dark habitats in warm regions; distinct from the phylum Annelida; resemble slugs with legs and are sometimes described as the missing link between arthropods and annelids
class Ophiuroidea: brittle stars and basket stars
class Osteichthyes: a class of fish having a skeleton composed of bone in addition to cartilage
class Pauropoda: an obscure class of minute arthropods with branched antennae and 8 to 10 pairs of legs
class Phaeophyceae: brown algae; mostly marine and littoral eukaryotic algae
class Phasmidia: one of two subgroups of Nematoda used in some classification systems
class Placodermi: extinct group of bony-plated fishes with primitive jaws
class Polychaeta: marine annelid worms
class Polyplacophora: small class of marine mollusks comprising the chitons; sometimes considered an order of the subclass Amphineura
class Reptilia: class of cold-blooded air-breathing vertebrates with completely ossified skeleton and a body usually covered with scales or horny plates; once the dominant land animals
class Rhodophyceae: coextensive with the Rhodophyta: red algae
class Sarcodina: characterized by the formation of pseudopods for locomotion and taking food: Actinopoda; Rhizopoda
class Scaphopoda: small class of bilaterally symmetrical marine forms comprising the tooth shells
class Schizomycetes: a former classification
class Scyphozoa: coelenterates in which the polyp stage is absent or at least inconspicuous: jellyfishes
class Sporozoa: strictly parasitic protozoans that are usually immobile; includes plasmodia and coccidia and piroplasms and malaria parasites
class Symphyla: small class of minute arthropods; unimportant except for the garden centipede
class Tardigrada: in some classifications considered a separate phylum: microscopic arachnid-like invertebrates living in water or damp moss having 4 pairs of legs and instead of a mouth a pair of stylets or needlelike piercing organs connected with the pharynx
class Tentaculata: ctenophores have retractile tentacles
class Thaliacea: small class of free-swimming tunicates; sometimes classified as an order
class Trematoda: parasitic flatworms (including flukes)
class Turbellaria: free-living flatworms
class Ulvophyceae: alternative name for the class Chlorophyceae in some classifications
class Xanthophyceae: yellow-green algae
claw: sharp curved horny process on the toe of a bird or some mammals or reptiles
claw: a bird's foot
cleg: large swift fly the female of which sucks blood of various animals
clerid: predacious on other insects; usually brightly colored or metallic
click beetle: able to right itself when on its back by flipping into the air with a clicking sound
climbing salamander: any of several North American salamanders adapted for climbing with well-developed limbs and long somewhat squared-off toes
clingfish: very small (to 3 inches) flattened marine fish with a sucking disc on the abdomen for clinging to rocks etc.
clinid: mostly small blennioid fishes of coral reefs and seagrass beds
clostridia: spindle-shaped bacterial cell especially one swollen at the center by an endospore
Clostridium botulinum: anaerobic bacterium producing botulin the toxin that causes botulism
clostridium perfringens: anaerobic Gram-positive rod bacterium that produces epsilon toxin; can be used as a bioweapon
clothes moth: any of several small yellowish or buff-colored moths whose larvae eat organic matter e.g. woolens
cloven foot: a hoof divided into two parts at its distal extremity (as of ruminants or swine)
clumber: a thickset spaniel with longish silky hair
Clupea harangus: commercially important food fish of northern waters of both Atlantic and Pacific
Clupea harengus harengus: important food fish; found in enormous shoals in the northern Atlantic
Clupea harengus pallasii: important food fish of the northern Pacific
Clupea sprattus: small herring processed like a sardine
clupeid: any of numerous soft-finned schooling food fishes of shallow waters of northern seas
Clydesdale: heavy feathered-legged breed of draft horse originally from Scotland
Clydesdale terrier: selectively bred small Skye terrier with erect ears and a long silky coat
clypeus: a shield-like plate on the front of an insect's head
CMV: any of a group of herpes viruses that enlarge epithelial cells and can cause birth defects; can affect humans with impaired immunological systems
Cnemidophorus sexlineatus: very swift lizard of eastern and central United States
Cnemidophorus tesselatus: markings are darker and more marked than in western whiptail; from southeastern Colorado to eastern Chihuahua
Cnemidophorus tigris: active lizard having a network of dusky dark markings; of semiarid areas from Oregon and Idaho to Baja California
Cnemidophorus velox: having distinct longitudinal stripes: of Colorado Plateau from Arizona to western Colorado
cnidarian: radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms
coach horse: strong draft horse for drawing coaches
coastal diving bird: gull family; skimmer family; jaeger family; auk family
coat: growth of hair or wool or fur covering the body of an animal
cob: adult male swan
cob: stocky short-legged harness horse
cobra: venomous Asiatic and African elapid snakes that can expand the skin of the neck into a hood
cocci: any spherical or nearly spherical bacteria
coccid insect: scale insects and mealybugs
coccidium: parasitic on the digestive epithelium of vertebrates and higher invertebrates
coccobacillus: a bacterial cell intermediate in morphology between a coccus and a bacillus; a very short bacillus
Coccothraustes coccothraustes: a common large finch of Eurasia
Coccus hesperidum: pest on citrus trees
Coccyzus erythropthalmus: North American cuckoo; builds a nest and rears its own young
cochin: Asian breed of large fowl with dense plumage and feathered legs
Cochlearius cochlearius: tropical American heron related to night herons
cock: adult male bird
cock: adult male chicken
cockatoo: white or light-colored crested parrot of the Australian region; often kept as cage birds
cockerel: a young domestic cock; not older than one year
cockle: common edible, burrowing European bivalve mollusk that has a strong, rounded shell with radiating ribs
cockroach: any of numerous chiefly nocturnal insects; some are domestic pests
cockscomb: the fleshy red crest on the head of the domestic fowl and other gallinaceous birds
cocoon: silky envelope spun by the larvae of many insects to protect pupas and by spiders to protect eggs
cod: major food fish of Arctic and cold-temperate waters
codling: young codfish
coelenterate family: a family of coelenterates
coelenterate genus: a genus of coelenterates
coelenteron: the saclike body cavity of a coelenterate
coelophysis: one of the oldest known dinosaurs; late Triassic; cannibalistic
Colaptes auratus: large flicker of eastern North America with a red neck and yellow undersurface to wings and tail
Colaptes caper collaris: western United States bird with red undersurface to wings and tail
Colaptes chrysoides: southwestern United States bird like the yellow-shafted flicker but lacking the red neck
Colinus virginianus: a favorite game bird of eastern and central United States
coliphage: a bacteriophage that infects the bacterium Escherichia coli
collared lizard: any of several robust long-tailed lizards with collars of two dark bands; of central and western United States and northern Mexico
collembolan: any of numerous minute wingless primitive insects possessing a special abdominal appendage that allows the characteristic nearly perpetual springing pattern; found in soil rich in organic debris or on the surface of snow or water
collie: a silky-coated sheepdog with a long ruff and long narrow head developed in Scotland
Collocalia inexpectata: swift of eastern Asia; produces the edible bird's nest
Colobus guereza: a colobus monkey with a reddish brown coat and white silky fringes down both sides of the body
colobus: arboreal monkey of western and central Africa with long silky fur and reduced thumbs
colt: a young male horse under the age of four
Coluber constrictor: blackish racer of the eastern United States that grows to six feet
Coluber constrictor flaviventris: bluish-green blacksnake found from Ohio to Texas
Coluber hippocrepis: slender fast-moving Eurasian snake
colubrid: mostly harmless temperate-to-tropical terrestrial or arboreal or aquatic snakes
colugo: arboreal nocturnal mammal of southeast Asia and the Philippines resembling a lemur and having a fold of skin on each side from neck to tail that is used for long gliding leaps
Columba fasciata: wild pigeon of western North America; often mistaken for the now extinct passenger pigeon
Columba livia: pale grey Eurasian pigeon having black-striped wings from which most domestic species are descended
Columba palumbus: Eurasian pigeon with white patches on wings and neck
columbiform bird: a cosmopolitan order of land birds having small heads and short legs with four unwebbed toes
comatulid: free-swimming stalkless crinoid with ten feathery arms; found on muddy sea bottoms
comb: ciliated comb-like swimming plate of a ctenophore
comb jelly: biradially symmetrical hermaphroditic solitary marine animals resembling jellyfishes having for locomotion eight rows of cilia arranged like teeth in a comb
comb-footed spider: spider having a comb-like row of bristles on each hind foot
comb-plate: a locomotor organ consisting of a row of strong cilia whose bases are fused
commensal: either of two different animal or plant species living in close association but not interdependent
common American shad: shad of Atlantic coast of North America; naturalized to Pacific coast
common eel: eels that live in fresh water as adults but return to sea to spawn; found in Europe and America; marketed both fresh and smoked
common European earwig: sometimes destructive to cultivated bulbs
common European jay: fawn-colored jay with black-and-white crest and blue-and-black wings
compsognathus: very small bipedal carnivorous dinosaur of the late Jurassic in Bavaria
conceptus: an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life
conch: any of various edible tropical marine gastropods of the genus Strombus having a brightly-colored spiral shell with large outer lip
condor: the largest flying birds in the western hemisphere
Condylura cristata: amphibious mole of eastern North America having pink fleshy tentacles around the nose
Conepatus leuconotus: large naked-muzzled skunk with white back and tail; of southwestern North America and Mexico
coney: any of several small ungulate mammals of Africa and Asia with rodent-like incisors and feet with hooflike toes
coney: small short-eared burrowing mammal of rocky uplands of Asia and western North America
coney: any of various burrowing animals of the family Leporidae having long ears and short tails; some domesticated and raised for pets or food
conferva: any of various algae of the genus Tribonema; algae with branching filaments that form scum in still or stagnant fresh water
confervoid algae: algae resembling confervae especially in having branching filaments
congenator: an animal or plant that bears a relationship to another (as related by common descent or by membership in the same genus)
conger: large dark-colored scaleless marine eel found in temperate and tropical coastal waters; some used for food
conodont: small (2 inches long) extinct eellike fish with a finned tail and a notochord and having cone-shaped teeth containing cellular bone; late Cambrian to late Triassic; possible predecessor of the cyclostomes
conodont: the tiny fossil cone-shaped tooth of a primitive vertebrate of order Conodonta
conspecific: an organism belonging to the same species as another organism
constrictor: any of various large nonvenomous snakes that kill their prey by crushing it in its coils
Constrictor constrictor: very large boa of tropical America and West Indies
Contopus sordidulus: small flycatcher of western North America
Contopus virens: small olive-colored woodland flycatchers of eastern North America
contour feather: feathers covering the body of an adult bird and determining its shape
Conuropsis carolinensis: extinct parakeet whose range extended far into the United States
coondog: any dog trained to hunt raccoons
coonhound: any of several breeds of hound developed for hunting raccoons
coot: slate-black slow-flying birds somewhat resembling ducks
copepod: minute marine or freshwater crustaceans usually having six pairs of limbs on the thorax; some abundant in plankton and others parasitic on fish
copper: any of various small butterflies of the family Lycaenidae having coppery wings
Coracias garrulus: common European blue-and-green roller with a reddish-brown back
coraciiform bird: chiefly short-legged arboreal nonpasserine birds that nest in holes
Coragyps atratus: American vulture smaller than the turkey buzzard
coral: marine colonial polyp characterized by a calcareous skeleton; masses in a variety of shapes often forming reefs
Coregonus artedi: important food fish of cold deep lakes of North America
Coregonus clupeaformis: found in the Great Lakes and north to Alaska
coreid: a true bug
cornetfish: slender tropical fish with a long tubular snout and bony plates instead of scales
Cornish fowl: English breed of compact domestic fowl; raised primarily to crossbreed to produce roasters
coronet: margin between the skin of the pastern and the horn of the hoof
corvine bird: birds of the crow family
Corvus brachyrhyncos: common crow of North America
Corvus corax: large black bird with a straight bill and long wedge-shaped tail
Corvus frugilegus: common gregarious Old World bird about the size and color of the American crow
Corvus monedula: common black-and-grey Eurasian bird noted for thievery
Corydalus cornutus: large soft-bodied insect having long slender mandibles in the male; aquatic larvae often used as bait
corynebacterium: any species of the genus Corynebacterium
Corynebacterium diphtheriae: a species of bacterium that causes diphtheria
Coryphaena equisetis: a kind of dolphinfish
Coryphaena hippurus: the more common dolphinfish valued as food; about six feet long
corythosaur: duck-billed dinosaur with nasal passages that expand into a crest like a hollow helmet
coscoroba: large white South American bird intermediate in some respects between ducks and swans
cosmid: (genetics) a large vector that is made from a bacteriophage and used to clone genes or gene fragments
Cosmocampus profundus: a fish 8 inches long; found from eastern Florida to western Caribbean
Costia necatrix: a flagellate that is the cause of the frequently fatal fish disease costiasis
Cotswold: sheep with long wool originating in the Cotswold Hills
cotton stainer: a true bug: bug that damages and stains the lint of developing cotton
cotton strain: feeds primarily on cotton
cottontail: common small rabbit of North America having greyish or brownish fur and a tail with a white underside; a host for Ixodes pacificus and Ixodes scapularis (Lyme disease ticks)
Coturnix coturnix: the typical Old World quail
coucal: Old World ground-living cuckoo having a long dagger-like hind claw
Count Fleet: thoroughbred that won the triple crown in 1943
courser: swift-footed terrestrial plover-like bird of southern Asia and Africa; related to the pratincoles
courser: a dog trained for coursing
cow: mature female of mammals of which the male is called `bull'
cow pony: a light saddle horse trained for herding cattle
cow: female of domestic cattle:
cowbird: North American blackbird that follows cattle and lays eggs in other birds' nests
cowrie: any of numerous tropical marine gastropods of the genus Cypraea having highly polished usually brightly marked shells
Coxsackie virus: enterovirus causing a disease resembling poliomyelitis but without paralysis
coydog: offspring of a coyote and a dog
crab: decapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers
crab-eating opossum: South American opossum
crabeater seal: silvery grey Antarctic seal subsisting on crustaceans
crake: any of several short-billed Old World rails
crampfish: any sluggish bottom-dwelling ray of the order Torpediniformes having a rounded body and electric organs on each side of the head capable of emitting strong electric discharges
crane: large long-necked wading bird of marshes and plains in many parts of the world
crane fly: long-legged slender flies that resemble large mosquitoes but do not bite
craniate: animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium
crappie: small sunfishes of central United States rivers
craw: a pouch in many birds and some lower animals that resembles a stomach for storage and preliminary maceration of food
crawdad: small freshwater decapod crustacean that resembles a lobster
crawfish: large edible marine crustacean having a spiny carapace but lacking the large pincers of true lobsters
creeper: any of various small insectivorous birds of the northern hemisphere that climb up a tree trunk supporting themselves on stiff tail feathers and their feet
creepy-crawly: an animal that creeps or crawls (such as worms or spiders or insects)
crest: a showy growth of e.g. feathers or skin on the head of a bird or other animal
crested penguin: small penguin of the Falkland Islands and New Zealand
crested screamer: distinguished from the horned screamer by a feathery crest on the back of the head
crested swift: birds of southeast Asia and East Indies differing from true swifts in having upright crests and nesting in trees
Crex crex: common Eurasian rail that frequents grain fields
Cricetus cricetus: a variety of hamster common to Europe and Asia
cricket: leaping insect; male makes chirping noises by rubbing the forewings together
cricket frog: either of two frogs with a clicking call
crinoid: primitive echinoderms having five or more feathery arms radiating from a central disk
critter: a regional term for `creature' (especially for domestic animals)
Cro-magnon: extinct human of Upper Paleolithic in Europe
croaker: any of several fishes that make a croaking noise
Crocethia alba: small sandpiper that breeds in the Arctic and migrates southward along sandy coasts in most of world
crocodile: large voracious aquatic reptile having a long snout with massive jaws and sharp teeth and a body covered with bony plates; of sluggish tropical waters
crocodilian: extant archosaurian reptile
Crocodylus niloticus: a dangerous crocodile widely distributed in Africa
Crocodylus porosus: estuarine crocodile of eastern Asia and Pacific islands
Crocuta crocuta: African hyena noted for its distinctive howl
cross: (genetics) an organism that is the offspring of genetically dissimilar parents or stock; especially offspring produced by breeding plants or animals of different varieties or breeds or species
crossopterygian: any fish of the order Crossopterygii; most known only in fossil form
Crotalus adamanteus: large deadly rattlesnake with diamond-shaped markings
Crotalus cerastes: small pale-colored desert rattlesnake of southwestern United States; body moves in an s-shaped curve
Crotalus horridus atricaudatus: southern variety
Crotalus horridus horridus: widely distributed in rugged ground of eastern United States
Crotalus lepidus: mountain rock dweller of Mexico and most southern parts of United States southwest
Crotalus mitchellii: markings vary but usually harmonize with background; of southwestern Arizona and Baja California
Crotalus scutulatus: extremely dangerous; most common in areas of scattered scrubby growth; from Mojave Desert to western Texas and into Mexico
Crotalus tigris: having irregularly cross-banded back; of arid foothills and canyons of southern Arizona and Mexico
croup: the part of an animal that corresponds to the human buttocks
crow: black birds having a raucous call
crow blackbird: long-tailed American blackbird having iridescent black plumage
crowbait: an emaciated horse likely soon to become carrion and so attractive to crows
crucifix fish: sea catfish of the Caribbean area
crustacean: any mainly aquatic arthropod usually having a segmented body and chitinous exoskeleton
Cryptacanthodes maculatus: eellike Atlantic bottom fish with large almost vertical mouth
Cryptobranchus alleganiensis: large salamander of North American rivers and streams
cryptomonad: common in fresh and salt water appearing along the shore as algal blooms
Cryptoprocta ferox: largest carnivore of Madagascar; intermediate in some respects between cats and civets
Cryptotermes brevis: extremely destructive dry-wood termite of warm regions
Cryptotis parva: small brown shrew of grassy regions of eastern United States
ctenidium: comb-like respiratory structure serving as the gill of certain mollusks
Ctenocephalides canis: flea that attacks dogs and cats
Ctenocephalides felis: flea that breeds chiefly on cats and dogs and rats
ctenophore family: a family of ctenophores
ctenophore genus: a genus of ctenophores
cub: the young of certain carnivorous mammals such as the bear or wolf or lion
cuckoo: any of numerous European and North American birds having pointed wings and a long tail
cuckoo-bumblebee: a bee that is parasitic in the nests of bumblebees
cuculiform bird: birds having zygodactyl feet (except for the touracos)
Culex pipiens: common house mosquito
Culex quinquefasciatus: widespread tropical mosquito that transmits filarial worms
Cuniculus paca: large burrowing rodent of South America and Central America; highly esteemed as food
Cuon alpinus: fierce wild dog of the forests of central and southeast Asia that hunts in packs
cupule: a sucker on the feet of certain flies
cur: an inferior dog or one of mixed breed
curassow: large crested arboreal game bird of warm parts of the Americas having long legs and tails; highly esteemed as game and food
curlew: large migratory shorebirds of the sandpiper family; closely related to woodcocks but having a down-curved bill
curly-coated retriever: an English breed having a tightly curled black or liver-colored coat; retrieves game from land or water
Cursorius cursor: courser of desert and semidesert regions of the Old World
cuscus: woolly-haired monkey-like arboreal marsupial of New Guinea and northern Australia
cusk-eel: elongate compressed somewhat eel-shaped fishes
cuticula: the outer body wall of an insect
cutlassfish: long-bodied marine fishes having a long whiplike scaleless body and sharp teeth; closely related to snake mackerel
cuttle: ten-armed oval-bodied cephalopod with narrow fins as long as the body and a large calcareous internal shell
cutworm: North American moth whose larvae feed on young plant stems cutting them off at the ground
Cyanocitta cristata: common jay of eastern North America; bright blue with grey breast
Cyclopes didactylus: squirrel-sized South American toothless anteater with long silky golden fur
cyclops: minute free-swimming freshwater copepod having a large median eye and pear-shaped body and long antennae used in swimming; important in some food chains and as intermediate hosts of parasitic worms that affect man e.g. Guinea worms
Cyclopterus lumpus: clumsy soft thick-bodied northern Atlantic fish with pelvic fins fused into a sucker; edible roe used for caviar
cyclostome: primitive aquatic vertebrate
cygnet: a young swan
Cygnus atratus: large Australian swan having black plumage and a red bill
Cygnus buccinator: large pure white wild swan of western North America having a sonorous cry
Cygnus columbianus: swan that nests in tundra regions of the New and Old Worlds
Cygnus columbianus bewickii: Eurasian subspecies of tundra swan; smaller than the whooper
Cygnus columbianus columbianus: North American subspecies of tundra swan having a soft whistling note
Cygnus cygnus: common Old World swan noted for its whooping call
Cygnus olor: soundless Eurasian swan; commonly domesticated
cynipid gall wasp: small solitary wasp that produces galls on oaks and other plants
Cynocephalus variegatus: a variety of flying lemur
cynodont: small carnivorous reptiles
Cynomys gunnisoni: tail is white tipped
Cynomys ludovicianus: tail is black tipped
Cynopterus sphinx: a variety of fruit eating bat
Cynoscion nebulosus: weakfish of southern Atlantic and Gulf Coasts of United States
Cynoscion regalis: food and game fish of North American coastal waters with a mouth from which hooks easily tear out
Cypraea moneta: cowrie whose shell is used for money in parts of the southern Pacific and in parts of Africa
Cypraea tigris: cowrie whose shell is used for ornament
cyprinid: soft-finned mainly freshwater fishes typically having toothless jaws and cycloid scales
cypriniform fish: a soft-finned fish of the order Cypriniformes
cyprinodont: any member of the family Cyprinodontidae
Cyprinus carpio: large Old World freshwater bottom-feeding fish introduced into Europe from Asia; inhabits ponds and sluggish streams and often raised for food; introduced into United States where it has become a pest
Cystophora cristata: medium-sized blackish-grey seal with large inflatable sac on the head; of Arctic and northern Atlantic waters
cytostome: mouth of a protozoan
dabbler: any of numerous shallow-water ducks that feed by upending and dabbling
Dacelo gigas: Australian kingfisher having a loud cackling cry
Dactylopius coccus: Mexican red scale insect that feeds on cacti; the source of a red dye
dairy cattle: cattle that are reared for their milk
dam: female parent of an animal especially domestic livestock
Dama dama: small Eurasian deer
Damaliscus lunatus: a large South African antelope; considered the swiftest hoofed mammal
Damaraland mole rat: colonial mole rat of western Africa; similar to naked mole rat
damselfish: small brilliantly colored tropical marine fishes of coral reefs
damselfly: slender non-stinging insect similar to but smaller than the dragonfly but having wings folded when at rest
danaid: large tropical butterfly with degenerate forelegs and an unpleasant taste
Danaus plexippus: large migratory American butterfly having deep orange wings with black and white markings; the larvae feed on milkweed
Dandie Dinmont terrier: a breed of small terrier with long wiry coat and drooping ears
daphnia: minute freshwater crustacean having a round body enclosed in a transparent shell; moves about like a flea by means of hairy branched antennae
dark horse: a racehorse about which little is known
darkling beetle: sluggish hard-bodied black terrestrial weevil whose larvae feed on e.g. decaying plant material or grain
darning needle: slender-bodied non-stinging insect having iridescent wings that are outspread at rest; adults and nymphs feed on mosquitoes etc.
darter: a person or other animal that moves abruptly and rapidly
Dasyatis centroura: one of the largest stingrays; found from Cape Cod to Cape Hatteras
Dasyprocta aguti: agile long-legged rabbit-sized rodent of Central America and South America and the West Indies; valued as food
Dasypus novemcinctus: having nine hinged bands of bony plates; ranges from Texas to Paraguay
dasyure: any of several more or less arboreal marsupials somewhat resembling martens
dasyurid: small carnivorous nocturnal marsupials of Australia and Tasmania
Dasyurus quoll: a variety of dasyure
Dasyurus viverrinus: carnivorous arboreal cat-like marsupials of Australia and Tasmania
Daubentonia madagascariensis: nocturnal lemur with long bony fingers and rodent-like incisor teeth closely related to the lemurs
dawn horse: earliest horse; extinct primitive dog-sized four-toed Eocene animal
dayfly: slender insect with delicate membranous wings having an aquatic larval stage and terrestrial adult stage usually lasting less than two days
decapod: cephalopods having eight short tentacles plus two long ones
decapod: crustaceans characteristically having five pairs of locomotor appendages each joined to a segment of the thorax
Decapterus macarellus: small silvery fish; Nova Scotia to Brazil
Decapterus punctatus: small fusiform fish of western Atlantic
definitive host: the host in which the sexual reproduction of a parasite takes place
defoliator: an insect that strips the leaves from plants
deinocheirus: lightly built medium-sized theropod with long limbs and neck
deinonychus: swift agile wolf-sized bipedal dinosaur having a large curved claw on each hind foot; of the Cretaceous
Delichon urbica: common small European martin that builds nests under the eaves of houses
Delphinapterus leucas: small northern whale that is white when adult
Delphinus delphis: black-and-white dolphin that leaps high out of the water
Dendroaspis augusticeps: a highly venomous southern African mamba dreaded because of its quickness and readiness to bite
Dendroctonus rufipennis: small beetle that likes to bore through the bark of spruce trees and eat the cambium which eventually kills the tree
Dendroica auduboni: common warbler of western North America
Dendroica coronata: similar to Audubon's warbler
Dendroica petechia: yellow-throated American wood warbler
Dendroica striate: North American warbler having a black-and-white head
Dendroica tigrina: North American wood warbler; olive green and yellow striped with black
Denisonia superba: venomous but sluggish reddish-brown snake of Australia
denizen: a plant or animal naturalized in a region
denticle: small pointed ridge on the exoskeleton of an arthropod
Dermacentor variabilis: common tick that can transmit Rocky Mountain spotted fever and tularemia
Dermatobia hominis: large tropical American fly; parasitic on humans and other mammals
Dermochelys coriacea: wide-ranging marine turtle with flexible leathery carapace; largest living turtle
desmid: freshwater green algae
Desmodus rotundus: mouse-sized bat of tropical Central America and South America having sharp incisor and canine teeth; feeds on the blood of birds and mammals
devilfish: extremely large pelagic tropical ray that feeds on plankton and small fishes; usually harmless but its size make it dangerous if harpooned
devilfish: bottom-living cephalopod having a soft oval body with eight long tentacles
Devon: red dual-purpose cattle of English origin
Dialeurodes citri: whitefly that attacks citrus trees
Diapheromera femorata: a variety of stick insect
diapsid: reptile having a pair of openings in the skull behind each eye
diatom: microscopic unicellular marine or freshwater colonial alga having cell walls impregnated with silica
dibranch: cephalopods having two gills
dicamptodon: salamanders found near cold streams throughout the year
Diceros bicornis: African rhino; in danger of extinction
dickeybird: small bird; adults talking to children sometimes use these words to refer to small birds
dictyopterous insect: cockroaches and mantids
dicynodont: a kind of therapsid
Didelphis marsupialis: omnivorous opossum of the eastern United States; noted for feigning death when in danger; esteemed as food in some areas; considered same species as the crab-eating opossum of South America
difflugia: a protozoan with an ovoid shell of cemented sand grains
digger wasp: solitary wasp that digs nests in the soil and stocks them with paralyzed insects for the larvae
digitigrade: an animal that walks so that only the toes touch the ground as e.g. dogs and cats and horses
dihybrid: a hybrid produced by parents that differ only at two gene loci that have two alleles each
dik-dik: any of several small antelopes of eastern Africa of the genus Madoqua; the size of a large rabbit
dimetrodon: carnivorous dinosaur of the Permian in North America having a crest or dorsal sail
dinoceras: a variety of dinocerate
dinocerate: an extinct ungulate
dinoflagellate: chiefly marine protozoa having two flagella; a chief constituent of plankton
Dinornis giganteus: the largest moa; about 12 feet high
dinosaur: any of numerous extinct terrestrial reptiles of the Mesozoic era
Diodon holocanthus: similar to but smaller than porcupinefish
Diodon hystrix: spines become erect when the body is inflated; worldwide in warm waters
Diomedea exulans: very large albatross; white with wide black wings
Diomedea nigripes: a variety of albatross with black feet
Diphylla ecaudata: similar in size and habits to Desmodus rotundus; of tropical America including southern California and Texas
diplococcus: Gram-positive bacteria usually occurring in pairs
Diplococcus pneumoniae: bacterium causing pneumonia in mice and humans
diplodocus: a huge quadrupedal herbivore with long neck and tail; of late Jurassic in western North America
diploid: (genetics) an organism or cell having the normal amount of DNA per cell; i.e., two sets of chromosomes or twice the haploid number
Dipodomys phillipsii: any of various leaping rodents of desert regions of North America and Mexico; largest members of the family Heteromyidae
dipper: small stocky diving bird without webbed feet; frequents fast-flowing streams and feeds along the bottom
Dipsosaurus dorsalis: small long-tailed lizard of arid areas of southwestern United States and northwestern Mexico
dipteran: insects having usually a single pair of functional wings (anterior pair) with the posterior pair reduced to small knobbed structures and mouth parts adapted for sucking or lapping or piercing
diver: large somewhat primitive fish-eating diving bird of the northern hemisphere having webbed feet placed far back; related to the grebes
diving duck: any of various ducks of especially bays and estuaries that dive for their food
diving petrel: any of several small diving birds of southern hemisphere seas; somewhat resemble auks
division Archaebacteria: in some classifications considered a kingdom
division Chlorophyta: large division of chiefly freshwater eukaryotic algae that possess chlorophyll a and b, store food as starch, and cellulose cell walls; classes Chlorophyceae, Ulvophyceae, and Charophyceae; obviously ancestral to land plants
division Chrysophyta: mostly freshwater eukaryotic algae having the chlorophyll masked by brown or yellow pigment; yellow-green and golden-brown algae and diatoms: Xanthophyceae, Chrysophyceae, Bacillariophyceae; some classification systems superseded or subsumed by Heterokontophyta
division Cyanophyta: prokaryotic organisms sometimes considered a class or phylum or subkingdom; coextensive with the Cyanophyceae: cyanobacteria (blue-green algae)
division Cynodontia: a division of the order Therapsida from the Triassic period comprising small carnivorous tetrapod reptiles often with mammal-like teeth
division Dicynodontia: a division of Therapsida
division Eubacteria: one-celled monerans having simple cells with rigid walls and (in motile types) flagella
division Euglenophyta: free-swimming flagellate algae
division Heterokontophyta: algae having chlorophyll a and usually c, and flagella of unequal lengths; terminology supersedes Chrysophyta in some classifications
division Phaeophyta: coextensive with class Phaeophyceae; in some classifications subsumed in the division Heterokontophyta
division Protista: eukaryotic one-celled living organisms distinct from multicellular plants and animals: protozoa, slime molds, and eukaryotic algae
division Rhodophyta: lower plants; mostly marine and littoral eukaryotic algae
division Schizophyta: former term for the Cyanophyta
dobbin: a quiet plodding workhorse
Doberman pinscher: medium large breed of dog of German origin with a glossy black and tan coat; used as a watchdog
dobson: large brown aquatic larva of the dobsonfly; used as fishing bait
dock: the solid bony part of the tail of an animal as distinguished from the hair
doe: mature female of mammals of which the male is called `buck'
dog-day cicada: its distinctive song is heard during July and August
dogfish: any of several small sharks
dogie: motherless calf in a range herd of cattle
Dolichonyx oryzivorus: migratory American songbird
Dolichotis patagonum: hare-like rodent of the pampas of Argentina
doliolum: free-swimming oceanic tunicate with a barrel-shaped transparent body
dolphin: any of various small toothed whales with a beaklike snout; larger than porpoises
dolphin: large slender food and game fish widely distributed in warm seas (especially around Hawaii)
domestic animal: any of various animals that have been tamed and made fit for a human environment
domestic fowl: a domesticated gallinaceous bird thought to be descended from the red jungle fowl
domestic pigeon: domesticated pigeon raised for sport or food
Dominique: American breed of chicken having barred grey plumage raised for meat and brown eggs
Donald Duck: a fictional duck created in animated film strips by Walt Disney
dorbeetle: Old World dung beetle that flies with a droning sound
Dorking: an English breed of large domestic fowl having five toes (the hind toe doubled)
dormouse: small furry-tailed squirrel-like Old World rodent that becomes torpid in cold weather
dorsal fin: unpaired median fin on the backs of fishes and some other aquatic vertebrates that help to maintain balance
dory: marine fishes widely distributed in mid-waters and deep slope waters
dove: any of numerous small pigeons
dowitcher: shorebird of the sandpiper family that resembles a snipe
down: soft fine feathers
downy woodpecker: small North American woodpecker with black and white plumage and a small bill
Dracunculus medinensis: parasitic roundworm of India and Africa that lives in the abdomen or beneath the skin of humans and other vertebrates
draft animal: an animal used for pulling heavy loads
draft horse: horse adapted for drawing heavy loads
dragon: any of several small tropical Asian lizards capable of gliding by spreading winglike membranes on each side of the body
dragonet: small often brightly colored scaleless marine bottom-dwellers; found in tropical and warm temperate waters of Europe and America
drake: adult male of a wild or domestic duck
Dreissena polymorpha: inch long mollusk imported accidentally from Europe; clogs utility inlet pipes and feeds on edible freshwater mussels
driftfish: small (6 inches) tropical butterfishes found worldwide
driftfish: larger butterfishes of the western Atlantic from the New York area to the northern Gulf of Mexico
dromaeosaur: a kind of maniraptor
Dromaius novaehollandiae: large Australian flightless bird similar to the ostrich but smaller
drone: stingless male bee in a colony of social bees (especially honeybees) whose sole function is to mate with the queen
Drosophila melanogaster: small fruit fly used by Thomas Hunt Morgan in studying basic mechanisms of inheritance
drum: small to medium-sized bottom-dwelling food and game fishes of shallow coastal and fresh waters that make a drumming noise
dry-wood termite: any of various termites that live in and feed on dry wood that is not connected with the soil
Drymarchon corais: large dark-blue nonvenomous snake that invades burrows; found in southern North America and Mexico
Drymarchon corais couperi: a variety of indigo snake
dryopithecine: considered a possible ancestor to both anthropoid apes and humans
Dryopithecus Rudapithecus hungaricus: fossil hominoids from northern central Hungary; late Miocene
duck: small wild or domesticated web-footed broad-billed swimming bird usually having a depressed body and short legs
duck down: down of the duck
duck-billed dinosaur: any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic
duckling: young duck
dug: an udder or breast or teat
Dugong dugon: sirenian tusked mammal found from eastern Africa to Australia; the flat tail is bilobate
Dumetella carolinensis: North American songbird whose call resembles a cat's mewing
dun: horse of a dull brownish grey color
dung beetle: any of numerous beetles that roll balls of dung on which they feed and in which they lay eggs
Duplicidentata: in former classifications considered a suborder of Rodentia coextensive with the order Lagomorpha: gnawing animals
Durham: English breed of short-horned cattle
Dusicyon cancrivorus: wild dog of northern South America
dusky salamander: common North American salamander mottled with dull brown or greyish-black
dusky-footed wood rat: a wood rat with dusky feet
dwarf pocket rat: small silky-haired pouched rodent; similar to but smaller than kangaroo rats
Eacles imperialis: large American moth having yellow wings with purplish or brownish markings; larvae feed on e.g. maple and pine trees
eagle ray: powerful free-swimming tropical ray noted for `soaring' by flapping winglike fins; usually harmless but has venomous tissue near base of the tail as in stingrays
eaglet: a young eagle
eared seal: pinniped mammal having external ear flaps and hind limbs used for locomotion on land; valued for its soft underfur
earless lizard: any of several slender lizards without external ear openings: of plains of western United States and Mexico
earless seal: any of several seals lacking external ear flaps and having a stiff hairlike coat with hind limbs reduced to swimming flippers
earwig: any of numerous insects of the order Dermaptera having elongate bodies and slender many-jointed antennae and a pair of large pincers at the rear of the abdomen
Easter bunny: a rabbit that delivers Easter eggs
eastern kingbird: a kingbird that breeds in North America and winters in tropical America; distinguished by a white band on the tip of the tail
Ebola virus: a filovirus that causes Ebola hemorrhagic fever; carried by animals; can be used as a bioweapon
Echeneis naucrates: remoras found attached to sharks
Echidnophaga gallinacea: parasitic on especially the heads of chickens
echinococcus: tapeworms whose larvae are parasitic in humans and domestic animals
echinoderm: marine invertebrates with tube feet and five-part radially symmetrical bodies
echinoderm family: a family of echinoderms
echinoderm genus: a genus of echinoderms
Echinus esculentus: a sea urchin that can be eaten
echovirus: any of a group of viruses associated with various diseases including viral meningitis and mild respiratory disorders and diarrhea in newborn infants
ectoblast: the outer germ layer that develops into skin and nervous tissue
ectoparasite: any external parasitic organism (as fleas)
Ectopistes migratorius: gregarious North American migratory pigeon now extinct
ectoproct: sessile mossy aquatic animal having the anus of the polyp outside the crown of tentacles
ectotherm: an animal whose body temperature varies with the temperature of its surroundings; any animal except birds and mammals
edaphosaurus: heavy-bodied reptile with a dorsal sail or crest; of the late Paleozoic
edentate: primitive terrestrial mammal with few if any teeth; of tropical Central America and South America
Edmontonia: heavily armored and highly spiked dinosaur with semi-upright posture
edmontosaurus: duck-billed dinosaur from Canada found as a fossilized mummy with skin
eel: voracious snakelike marine or freshwater fishes with smooth slimy usually scaleless skin and having a continuous vertical fin but no ventral fins
eelblenny: eellike fishes found in subarctic coastal waters
eelpout: marine eellike mostly bottom-dwelling fishes of northern seas
eelworm: any of various small free-living plant-parasitic roundworms
eft: a newt in its terrestrial stage of development
egg: animal reproductive body consisting of an ovum or embryo together with nutritive and protective envelopes; especially the thin-shelled reproductive body laid by e.g. female birds
egg-laying mammal: the most primitive mammals comprising the only extant members of the subclass Prototheria
eggar: moth having nonfunctional mouthparts as adults; larvae feed on tree foliage and spin egg-shaped cocoons
egret: any of various usually white herons having long plumes during breeding season
Egretta caerulea: small bluish-grey heron of the western hemisphere
Egretta garzetta: Old World egret
Egretta thula: small New World egret
Egyptian cat: a domestic cat of Egypt
Egyptian cobra: cobra used by the Pharaohs as a symbol of their power over life and death
eider: duck of the northern hemisphere much valued for the fine soft down of the females
eiderdown: down of the eider duck
Eira barbara: long-tailed arboreal mustelid of Central America and South America
Elagatis bipinnulata: streamlined cigar-shaped jack; good game fish
eland: either of two large African antelopes of the genus Taurotragus having short spirally twisted horns in both sexes
Elanoides forficatus: graceful North American black-and-white kite
Elanus leucurus: grey-and-white American kite of warm and tropical regions
Elaphe guttata: large harmless snake of southeastern United States; often on farms
Elaphe obsoleta: large harmless shiny black North American snake
Elaphurus davidianus: large Chinese deer surviving only in domesticated herds
elapid: any of numerous venomous fanged snakes of warmer parts of both hemispheres
elasmobranch: any of numerous fishes of the class Chondrichthyes characterized by a cartilaginous skeleton and placoid scales: sharks; rays; skates
elater: any of various widely distributed beetles
elbow: the joint of a mammal or bird that corresponds to the human elbow
Electrophorus electric: eel-shaped freshwater fish of South America having electric organs in its body
elephant: five-toed pachyderm
elephant seal: either of two large northern Atlantic earless seals having snouts like trunks
Elops saurus: game fish resembling the tarpon but smaller
elver: young eel
elytron: either of the horny front wings in beetles and some other insects which cover and protect the functional hind wings
Emberiza aureola: common in Russia and Siberia
Emberiza citrinella: European bunting the male being bright yellow
Emberiza hortulana: brownish Old World bunting often eaten as a delicacy
Emberiza schoeniclus: European bunting inhabiting marshy areas
embryonic tissue: tissue in an embryo
emperor: large richly colored butterfly
encolure: the mane of a horse
endameba: any ameba of the genus Endamoeba
Endamoeba histolytica: the parasitic ameba that causes amebic dysentery in human beings
endoblast: the inner germ layer that develops into the lining of the digestive and respiratory systems
endoparasite: any of various parasites that live in the internal organs of animals (especially intestinal worms)
endospore-forming bacteria: a group of true bacteria
English bulldog: a sturdy thickset short-haired breed with a large head and strong undershot lower jaw; developed originally in England for bull baiting
English cocker spaniel: a small breed with wavy silky hair; originally developed in England
English foxhound: an English breed slightly larger than the American foxhounds originally used to hunt in packs
English lady crab: crab of the English coasts
English setter: an English breed having a plumed tail and a soft silky coat that is chiefly white
English springer spaniel: a breed having typically a black-and-white coat
English toy spaniel: British breed having a long silky coat and rounded head with a short upturned muzzle
Engraulis encrasicholus: esteemed for its flavor; usually preserved or used for sauces and relishes
Enhydra lutris: large marine otter of northern Pacific coasts having very thick dark brown fur
enteric bacteria: rod-shaped Gram-negative bacteria; most occur normally or pathogenically in intestines of humans and other animals
Enterobius vermicularis: small threadlike worm infesting human intestines and rectum especially in children
enterovirus: any of a group of picornaviruses that infect the gastrointestinal tract and can spread to other areas (especially the nervous system)
entire: uncastrated adult male horse
EntleBucher: the smallest of the Sennenhunde
entoproct: any of various moss-like aquatic animals usually forming branching colonies; each polyp having a both mouth and anus within a closed ring of tentacles
eoraptor: a theropod dinosaur of the genus Eoraptor
ephemeral: anything short-lived, as an insect that lives only for a day in its winged form
ephemerid: short-lived insect
Ephestia elutella: small moth whose larvae feed on tobacco and other dried plant products
Ephippiorhynchus senegalensis: large black-and-white stork of tropical Africa; its red bill has a black band around the middle
Epilachna varivestis: introduced into the United States from Mexico; feeds on the foliage of the bean plant
Epinephelus adscensionis: found around rocky coasts or on reefs
Epinephelus fulvus: black-spotted usually dusky-colored fish with reddish fins
Epstein-Barr virus: the herpes virus that causes infectious mononucleosis; associated with specific cancers in Africa and China
eptatretus: a fossil hagfish of the genus Eptatretus
Eptesicus fuscus: rather large North American brown bat; widely distributed
Eptesicus serotinus: common brown bat of Europe
Equetus lanceolatus: black-and-white drumfish with an erect elongated dorsal fin
Equetus pulcher: a kind of drumfish
equid: hoofed mammals having slender legs and a flat coat with a narrow mane along the back of the neck
Equus asinus: domestic beast of burden descended from the African wild ass; patient but stubborn
Equus caballus: solid-hoofed herbivorous quadruped domesticated since prehistoric times
Equus caballus gomelini: European wild horse extinct since the early 20th century
Equus caballus przewalskii: wild horse of central Asia that resembles an ass; now endangered
Equus grevyi: zebra with less continuous stripes
Equus hemionus: Asiatic wild ass
Equus hemionus hemionus: Mongolian wild ass
Equus kiang: wild ass of Tibet and Mongolia
Equus quagga: mammal of South Africa that resembled a zebra; extinct since late 19th century
Equus zebra zebra: narrow-striped nearly extinct zebra of southern Africa
Erethizon dorsatum: porcupine of northeastern North America with barbed spines concealed in the coarse fur; often gnaws buildings for salt and grease
Eretmochelys imbricata: pugnacious tropical sea turtle with a hawk-like beak; source of food and the best tortoiseshell
Erignathus barbatus: medium-sized greyish to yellow seal with bristles each side of muzzle; of the Arctic Ocean
Erinaceus europeaeus: small nocturnal Old World mammal covered with both hair and protective spines
Eriosoma lanigerum: primarily a bark feeder on aerial parts and roots of apple and other trees
Erithacus rubecola: small Old World songbird with a reddish breast
Erithacus svecicus: songbird of northern Europe and Asia
Erolia alpina: small common sandpiper that breeds in northern or Arctic regions and winters in southern United States or Mediterranean regions
Erolia minutilla: smallest American sandpiper
erwinia: rod-shaped motile bacteria that attack plants
Erythrocebus patas: reddish long-tailed monkey of west Africa
escallop: edible marine bivalve having a fluted fan-shaped shell that swim by expelling water from the shell in a series of snapping motions
escherichia: a genus of enteric bacteria
Escherichia coli: a species of bacterium normally present in intestinal tract of humans and other animals; sometimes pathogenic; can be a threat to food safety
Eschrichtius robustus: medium-sized greyish-black whale of the northern Pacific
Eskimo dog: breed of heavy-coated Arctic sled dog
Esox americanus: small but gamy pickerel of Atlantic coastal states
Esox lucius: voracious piscivorous pike of waters of northern hemisphere
Esox masquinongy: large (60 to 80 pounds) sport fish of North America
Esox niger: common in quiet waters of eastern United States
Etropus rimosus: flounder found from North Carolina to Florida and the eastern Gulf of Mexico
Euarctos americanus: brown to black North American bear; smaller and less ferocious than the brown bear
eubacteria: a large group of bacteria having rigid cell walls; motile types have flagella
eucaryote: an organism with cells characteristic of all life forms except primitive microorganisms such as bacteria; i.e. an organism with `good' or membrane-bound nuclei in its cells
Eucinostomus gula: silvery mojarra found along sandy shores of the western Atlantic
Euderma maculata: a large bat of the southwestern United States having spots and enormous ears
euglena: minute single-celled green freshwater organism having a single flagella; often classed as algae
euglenid: marine and freshwater green or colorless flagellate organism
Eumeces callicephalus: frequents oak and pine habitats in rocky mountainous areas of United States southwest and Mexico
Eumeces skiltonianus: found in western North American grasslands and open woodlands
Eumetopias jubatus: largest sea lion; of the northern Pacific
Eunectes murinus: large arboreal boa of tropical South America
Euopean hoopoe: pinkish-brown hoopoe with black-and-white wings
Euphagus carilonus: North American blackbird whose bluish-black plumage is rusty-edged in the fall
Euphausia pacifica: food for jellyfish
Euphractus sexcinctus: Argentine armadillo with six movable bands and hairy underparts
Euproctis chrysorrhoea: white furry-bodied European moth with a yellow tail tuft
Euproctis phaeorrhoea: small brown and white European moth introduced into eastern United States; pest of various shade and fruit trees
Eurasian badger: a variety of badger native to Europe and Asia
Eurasian green toad: Eurasian toad with variable chiefly green coloring
Eurasian kingfisher: small kingfisher with greenish-blue and orange plumage
Eurasian otter: otter found in Europe and Asia
European black grouse: large northern European grouse that is black with a lyre-shaped tail
European blackbird: common black European thrush
European bream: European freshwater fish having a flattened body and silvery scales; of little value as food
European catfish: large elongated catfish of central and eastern Europe
European corn borer moth: native to Europe; in America the larvae bore into the stem and crown of corn and other plants
European cuckoo: common cuckoo of Europe having a distinctive two-note call; lays eggs in the nests of other birds
European fire salamander: a kind of European salamander
European house cricket: lives in human dwellings; naturalized in parts of America
European lemming: notable for mass migrations even into the sea where many drown
European magpie: a common magpie of Eurasia
European nuthatch: a kind of nuthatch
European sandpiper: a variety of sandpiper
European sole: highly valued as food
European spider crab: a large spider crab of Europe
European swift: common European bird with a shrieking call that nests chiefly about eaves of buildings or on cliffs
European toad: common toad of Europe
European tortoise: small land tortoise of southern Europe
European water ouzel: a water ouzel of Europe
European water shrew: widely distributed Old World water shrew
European wolf spider: large southern European spider once thought to be the cause of tarantism (uncontrollable bodily movement)
European wood mouse: nocturnal yellowish-brown mouse inhabiting woods and fields and gardens
eurypterid: large extinct scorpion-like arthropod considered related to horseshoe crabs
Eutamius sibiricus: terrestrial Siberian squirrel
eutherian: mammals having a placenta; all mammals except monotremes and marsupials
Euthynnus pelamis: oceanic schooling tuna of considerable value in Pacific but less in Atlantic; reaches 75 pounds; very similar to if not the same as oceanic bonito
ewe: female sheep
Exmoor: horned sheep of Devon; valued for mutton
Exmoor: stocky breed of pony with a fawn-colored nose
external gill: occurs in some mollusks and in tadpoles and other immature amphibians
eyas: an unfledged or nestling hawk
eyecup: (embryology) a two-walled cuplike depression that develops into the pigmented and sensory layers of the retina
fairy shrimp: small freshwater branchiopod having a transparent body with many appendages; swims on its back
fairy swallow: fancy domestic pigeon having blue-and-white plumage and heavily muffed feet
Falco columbarius: small falcon of Europe and America having dark plumage with black-barred tail; used in falconry
Falco peregrinus: a widely distributed falcon formerly used in falconry
Falco rusticolus: large and rare Arctic falcon having white and dark color phases
Falco sparverius: small North American falcon
Falco subbuteo: small Old World falcon formerly trained and flown at small birds
Falco tinnunculus: small Old World falcon that hovers in the air against a wind
falcon: diurnal birds of prey having long pointed powerful wings adapted for swift flight
falcon-gentil: female falcon especially a female peregrine falcon
fall cankerworm: green or brown white-striped looper; larva of Alsophila pometaria
false saber-toothed tiger: North American cat of the Miocene and Pliocene; much earlier and less specialized than members of the genus Smiledon
false scorpion: small nonvenomous arachnid resembling a tailless scorpion
false vampire: any New or Old World carnivorous bat erroneously thought to suck blood but in fact feeding on insects
family Acanthisittidae: alternative names for the family comprising the New Zealand wrens
family Acanthuridae: surgeonfishes
family Acaridae: mites
family Accipitridae: hawks; Old World vultures; kites; harriers; eagles
family Acipenseridae: sturgeons
family Actinomycetaceae: filamentous anaerobic bacteria
family Adelgidae: plant lice
family Aegypiidae: in some classifications considered the family comprising the Old World vultures which are more often included in the family Accipitridae
family Aepyornidae: coextensive with the order Aepyorniformes
family Agamidae: an Old World reptile family of Sauria
family Agonidae: poachers
family Ailuropodidae: in some classifications considered the family comprising the giant pandas
family Akeridae: bubble shells
family Alaudidae: larks
family Albulidae: bonefish
family Alcedinidae: kingfishers
family Alcidae: web-footed diving seabirds of northern seas: auks; puffins; guillemots; murres; etc.
family Aleyrodidae: whiteflies
family Alligatoridae: alligators; caimans
family Alopiidae: thresher sharks
family Ambystomatidae: New World salamanders
family Ameiuridae: North American catfishes
family Amiidae: only the bowfins
family Ammodytidae: sand lances
family Amphisbaenidae: worm lizards
family Amphiumidae: congo snakes
family Anabantidae: small freshwater spiny-finned fishes of Africa and southern Asia
family Anarhichadidae: wolffishes
family Anatidae: swimming birds having heavy short-legged bodies and bills with a horny tip: swans; geese; ducks
family Ancylidae: freshwater gastropod
family Ancylostomatidae: hookworms
family Andrenidae: a large family of solitary short-tongued bees most of which burrow in the ground
family Anguidae: alligator lizards
family Anguillidae: eels that live in fresh water as adults but return to the sea to spawn
family Anhimidae: screamers
family Anhingidae: snakebirds
family Anniellidae: legless lizards
family Anobiidae: deathwatch beetles
family Anomalopidae: a family of fish including: flashlight fishes
family Anomiidae: saddle oysters
family Antedonidae: feather stars
family Antennariidae: frogfishes; tropical spiny-finned marine fishes having large nearly vertical mouths; related to toadfishes and anglers
family Antilocapridae: comprising only the pronghorns
family Aphididae: small soft-bodied plant lice
family Apidae: honeybees; carpenter bees; bumblebees
family Aplodontiidae: mountain beavers
family Aplysiidae: sea hares
family Apodidae: swifts; in former classifications included in the order Coraciiformes
family Apogonidae: bright-colored marine fishes that incubate eggs in the mouth
family Apterygidae: coextensive with the order Apterygiformes
family Arcellidae: soil and freshwater protozoa; cosmopolitan in distribution
family Arcidae: ark shells
family Arctiidae: tiger moths
family Ardeidae: herons; egrets; night herons; bitterns
family Argasidae: soft ticks
family Argentinidae: small marine soft-finned fishes with long silvery bodies; related to salmons and trouts
family Argiopidae: spiders that spin orb webs; cosmopolitan in distribution
family Argonautidae: represented solely by the genus Argonauta
family Ariidae: sea catfishes
family Armadillidiidae: pill bugs
family Artamidae: wood swallows
family Ascaphidae: family of one species of frog: tailed frog
family Ascaridae: large roundworms parasitic in intestines of vertebrates
family Asilidae: robber flies
family Astacidae: crayfish
family Atherinidae: small spiny-finned fishes of both salt and fresh water
family Athiorhodaceae: small motile sulphur bacteria
family Atrichornithidae: scrubbirds
family Atropidae: booklice
family Aulostomidae: trumpetfishes
family Babesiidae: piroplasms and cattle pathogens
family Bacillaceae: typically rod-shaped usually Gram-positive bacteria that produce endospores
family Bacteroidaceae: family of bacteria living usually in the alimentary canal or on mucous surfaces of warm-blooded animals; sometimes associated with acute infective processes
family Balaenicipitidae: shoebills
family Balaenidae: right whales
family Balaenopteridae: rorquals; blue whales
family Balanidae: stalkless barnacles
family Balistidae: triggerfishes
family Bangiaceae: a family of protoctist
family Bathyergidae: mole rats; sand rats
family Batrachoididae: toadfishes; related to anglers and batfishes
family Belemnitidae: family of extinct Mesozoic cephalopods
family Belonidae: ferocious fishes of warm regions resembling but unrelated to the freshwater gars
family Belostomatidae: water bugs
family Bittacidae: a family of predacious tropical insects of the order Mecoptera
family Blattidae: domestic cockroaches
family Blenniidae: a family of fish including: combtooth blennies
family Boidae: boas and pythons
family Bombycidae: Chinese silkworm moth
family Bombycillidae: a family of birds of the suborder Oscines
family Bombyliidae: bee flies
family Bothidae: a family of fish of the order Heterosomata
family Bovidae: true antelopes; cattle; oxen; sheep; goats
family Bradypodidae: a family of edentates comprising the true sloths
family Bramidae: deep-bodied percoid fishes of the open seas
family Branchiobdellidae: small annelid worms with the posterior end modified into an adhesive sucker; especially formerly regarded as modified leeches
family Branchiostegidae: small family of marine fishes having covered gills
family Branchiostomidae: lancelets
family Brevicipitidae: narrow-mouthed toads and sheep frogs; some burrow and some are arboreal; found worldwide
family Brotulidae: chiefly deep-sea fishes related to the Ophidiidae
family Bruchidae: seed beetles
family Buccinidae: whelks
family Bucconidae: puffbirds
family Bucerotidae: hornbills
family Bufonidae: true toads
family Burhinidae: large wading birds resembling the plovers: stone curlews
family Caeciliadae: coextensive with the order Gymnophiona: legless amphibians
family Caenolestidae: small marsupials of southern South America
family Callionymidae: dragonets
family Calliphoridae: blowflies
family Callithricidae: marmosets
family Camelidae: camels and llamas and vicunas
family Cancridae: many of the best known edible crabs
family Canidae: dogs; wolves; jackals; foxes
family Capitonidae: barbets
family Caprimulgidae: goatsuckers
family Caproidae: boarfishes
family Capromyidae: coypus
family Capsidae: leaf bugs
family Carabidae: ground beetles
family Carangidae: large family of narrow-bodied marine food fishes with widely forked tails; chiefly of warm seas
family Carapidae: pearlfishes: related to the Brotulidae
family Carcharhinidae: largest family of living sharks; found worldwide especially in tropical waters; dorsal fin lacks spines: requiem sharks including tiger sharks and soupfin sharks
family Cardiidae: somewhat heart-shaped sand-burrowing bivalve mollusks
family Cariamidae: crane-like South American wading birds
family Castoridae: beavers
family Casuaridae: a family of large ostrich-like birds including cassowaries
family Cathartidae: condors; turkey buzzards; king vultures
family Catostomidae: suckers; closely related to the family Cyprinidae
family Caviidae: a family of Hystricomorpha
family Cebidae: all the New World monkeys except marmosets and tamarins
family Cecidomyidae: gall midges
family Centrarchidae: sunfish family
family Centriscidae: shrimpfishes
family Centropomidae: a family of fish or the order Perciformes including robalos
family Cephalobidae: a family of Nematoda
family Cerambycidae: long-horned beetles
family Ceratodontidae: lungfishes having hornlike ridges on the teeth
family Ceratopogonidae: biting midges; sand flies
family Ceratopsidae: American ceratopsian dinosaurs
family Cercopidae: froghoppers or spittlebugs
family Cercopithecidae: Old World monkeys: guenon; baboon; colobus monkey; langur; macaque; mandrill; mangabey; patas; proboscis monkey
family Certhiidae: creepers
family Cervidae: deer: reindeer; moose or elks; muntjacs; roe deer
family Cestidae: coextensive with the order Cestida; ctenophores having a greatly flattened and elongated body
family Cetorhinidae: in some older classifications considered the family of the basking sharks
family Chaetodontidae: butterfly fishes
family Chalcididae: an arthropod family including: chalcidflies
family Chamaeleontidae: Old World chameleons; in some classifications they are considered a superfamily of Sauria
family Characeae: green algae superficially resembling horsetail ferns: stoneworts
family Characidae: tropical freshwater fishes of Africa and South America and Central America
family Characinidae: former name of the Characidae
family Charadriidae: plover family
family Cheloniidae: green turtles; hawksbills
family Chelydridae: snapping turtles
family Chermidae: jumping plant lice
family Chimaeridae: a family of Holocephali
family Chinchillidae: small bushy-tailed South American burrowing rodents
family Chironomidae: midges
family Chlamydiaceae: Gram-negative parasites in warm-blooded vertebrates
family Chlamydomonadaceae: green algae some of which are colored red by hematochrome
family Chlorophthalmidae: small family of soft-finned bottom-dwellers with large eyes; relatives of lizardfishes
family Chrysochloridae: golden moles
family Chrysomelidae: leaf beetles
family Chrysopidae: green lacewings
family Cicadellidae: leafhoppers
family Cicadidae: cicadas
family Cichlidae: cichlids
family Cicindelidae: tiger beetles
family Ciconiidae: storks
family Cimicidae: wingless flat-bodied bloodsucking insects
family Cinclidae: water ouzels
family Cleridae: beetles that prey on other insects
family Clinidae: viviparous blennies of temperate and tropical seas
family Clupeidae: herrings; shad; sardines; etc.
family Cobitidae: loaches
family Coccidae: scale insects
family Coccinellidae: the ladybugs
family Coerebidae: the honeycreepers
family Colubridae: nonvenomous snakes; about two-thirds of all living species
family Columbidae: doves and pigeons
family Comatulidae: former usage synonymous with Antedonidae
family Congridae: marine eels
family Coraciidae: rollers
family Cordylidae: small family of spiny ovoviviparous African lizards
family Coregonidae: soft-finned fishes comprising the freshwater whitefishes; formerly included in the family Salmonidae
family Coreidae: squash bugs and leaf-footed bugs
family Corixidae: water bugs
family Corvidae: crow; raven; rook; jackdaw; chough; magpie; jay
family Corydalidae: dobsons
family Corynebacteriaceae: a large family of mostly Gram-positive and aerobic and nonmotile rod-shaped bacteria of the order Eubacteriales
family Coryphaenidae: large active pelagic percoid fish
family Cotingidae: cotingas; umbrella birds
family Cottidae: sculpins
family Cracidae: curassows; guans; chachalacas
family Cracticidae: Australian birds formerly included in the family Laniidae
family Crangonidae: shrimps
family Cricetidae: mostly small New World rodents including New World mice and lemmings and voles and hamsters
family Crocodylidae: true crocodiles
family Crotalidae: New World vipers: pit vipers
family Cryptobranchidae: large aquatic salamanders: hellbenders; giant salamanders
family Cryptocercidae: a family of Blattodea
family Ctenizidae: large burrowing spiders
family Cuculidae: includes cuckoo; ani; roadrunner
family Culicidae: mosquitoes
family Curculionidae: true weevils: snout beetles
family Cuterebridae: New World botflies
family Cyclopteridae: lumpfishes
family Cymatiidae: tritons
family Cynipidae: a family of Hymenoptera
family Cynocephalidae: a family of Dermoptera
family Cynoglossidae: tonguefishes
family Cypraeidae: family of marine gastropods comprising the cowries
family Cyprinidae: a family of fish including: carp; tench; roach; rudd; dace
family Cyprinodontidae: large family of small soft-finned fishes; killifishes; flagfishes; swordtails; guppies
family Dactylopiidae: cochineal insects
family Dactylopteridae: flying gurnards
family Dactyloscopidae: sand stargazers
family Danaidae: small family of usually tropical butterflies: monarch butterflies
family Dasyatidae: sting rays
family Dasypodidae: armadillos
family Dasyproctidae: agoutis and pacas
family Dasyuridae: dasyures; native cats; pouched mice; banded anteaters; Tasmanian devils
family Daubentoniidae: comprising solely the aye-aye
family Delphinidae: dolphins
family Dendrocolaptidae: woodhewers or woodcreepers
family Dermestidae: carpet beetles
family Dermochelyidae: sea turtles
family Desmidiaceae: unicellular algae
family Desmodontidae: true vampire bats
family Diaspididae: armored scales
family Dicamptodontidae: large and small highly aquatic salamanders
family Didelphidae: opossums
family Dinornithidae: moas
family Diodontidae: spiny puffers
family Diomedeidae: albatrosses
family Dipodidae: Old World jerboas
family Discoglossidae: family of Old World toads having a fixed disklike tongue
family Doliolidae: oceanic tunicates
family Dracunculidae: greatly elongated roundworm
family Drepanididae: Hawaiian honeycreepers
family Dromaeosauridae: swift-running bipedal dinosaurs
family Drosophilidae: fruit flies
family Dugongidae: a family of mammals of order Sirenia including dugongs and Steller's sea cow
family Dytiscidae: water beetles
family Echeneididae: fishes having a sucking disk on the head for clinging to other fishes and to ships
family Edaphosauridae: a family of reptiles of the order Pelycosauria
family Eimeriidae: a family of protoctist in the order Coccidia
family Elapidae: cobras; kraits; mambas; coral snakes; Australian taipan and tiger snakes
family Elateridae: click beetles and certain fireflies
family Electrophoridae: small family comprising the electric eels
family Eleotridae: sleepers
family Elephantidae: elephants
family Elopidae: tarpons and ladyfishes
family Embiotocidae: viviparous percoid fishes comprising the surf fishes
family Emydidae: box and water turtles
family Endamoebidae: a large family of endoparasitic amebas that invade the digestive tract
family Engraulidae: anchovies
family Enterobacteriaceae: a large family of Gram-negative rod-shaped bacteria of the order Eubacteriales
family Ephemeridae: mayflies
family Ephippidae: small family comprising the spadefishes
family Equidae: horses; asses; zebras; extinct animals
family Erethizontidae: New World arboreal porcupines
family Erinaceidae: true hedgehogs
family Eschrichtiidae: comprising only the grey whales
family Esocidae: pikes; pickerels; muskellunges
family Euglenaceae: considered green algae
family Eurylaimidae: coextensive with the suborder Eurylaimi
family Exocoetidae: flying fishes; closely related to the halfbeaks
family Falconidae: a family of birds of the order Falconiformes
family Fasciolidae: a family of Trematoda
family Felidae: cats; wildcats; lions; leopards; cheetahs; saber-toothed tigers
family Filariidae: threadlike roundworms
family Fissurellidae: marine limpets
family Fistulariidae: cornetfishes
family Forficulidae: typical earwigs
family Formicariidae: antbirds
family Formicidae: ants
family Fregatidae: frigate birds
family Fringillidae: finches: goldfinches; bullfinches; chaffinches; siskins; canaries; cardinals; grosbeaks; crossbills; linnets; buntings
family Fucaceae: small family of brown algae: gulfweeds; rockweeds
family Fulgoridae: plant hoppers: lantern flies
family Furnariidae: e.g. ovenbirds
family Gadidae: large family of important mostly marine food fishes
family Galbulidae: jacamars
family Gasterophilidae: horse botflies
family Gasterosteidae: sticklebacks
family Gavialidae: gavials
family Gavidae: loon family
family Gekkonidae: geckos
family Gelechiidae: important economic pests
family Gempylidae: snake mackerels
family Geometridae: measuring worms
family Geomyidae: North American pocket gophers
family Geophilidae: small extremely elongate centipedes that live in earth
family Gerreidae: mojarras
family Gerrididae: an arthropod family that includes water striders
family Gigartinaceae: a family of protoctist
family Giraffidae: giraffes
family Glareolidae: Old World shorebirds: pratincoles and coursers
family Gliridae: dormice and other Old World forms
family Globigerinidae: a family of protoctists
family Glossinidae: flies closely related to the Muscidae: tsetse flies
family Gobiesocidae: clingfishes
family Gobiidae: gobies
family Gomphotheriidae: elephants extinct since the Pleistocene
family Gonorhynchidae: coextensive with the genus Gonorhynchus
family Gracilariidae: leaf miners
family Gruidae: cranes
family Gryllidae: crickets
family Gyrinidae: whirligig beetles
family Hadrosauridae: duck-billed dinosaurs; upper Cretaceous
family Haematopodidae: oystercatchers
family Haemoproteidae: bird parasites
family Haemulidae: grunts
family Halictidae: a family of small solitary bees; many are valuable pollinators for agriculture
family Haliotidae: abalones
family Helicidae: land snails including the common edible snail and some pests
family Helodermatidae: only known venomous lizards
family Hemerobiidae: brown lacewings
family Hemiprocnidae: tree swifts
family Hemiramphidae: halfbeaks; marine and freshwater fishes closely related to the flying fishes but not able to glide
family Heteromyidae: small New World burrowing mouselike rodents with fur-lined cheek pouches and hind limbs and tail adapted to leaping; adapted to desert conditions: pocket mice; kangaroo mice; kangaroo rats
family Hexagrammidae: greenlings
family Hexanchidae: primitive sharks
family Hippoboscidae: winged or wingless dipterans: louse flies
family Hippopotamidae: hippopotami
family Hipposideridae: Old World leafnose bats
family Hirudinidae: a family of Hirudinea
family Hirundinidae: swallows and martins
family Holocentridae: squirrelfishes and soldierfishes
family Holothuridae: a family of Holothuroidea
family Homaridae: large-clawed lobsters
family Hominidae: modern man and extinct immediate ancestors of man
family Hyaenidae: hyenas
family Hydrobatidae: storm petrels
family Hydrochoeridae: capybara
family Hydrophidae: sea snakes
family Hylidae: the amphibian family of tree frogs
family Hylobatidae: used in some classifications for the lesser apes (gibbons and siamangs); sometimes considered a subfamily of Pongidae
family Hyperodontidae: beaked whales; in some especially former classifications included in the family Physeteridae
family Hypodermatidae: warble flies
family Hystricidae: Old World porcupines
family Ichneumonidae: ichneumon flies
family Ichthyosauridae: later ichthyosaurs of the Jurassic and Cretaceous; widely distributed in both hemispheres
family Icteridae: American orioles; American blackbirds; bobolinks; meadowlarks
family Iguanidae: New World lizards
family Iguanodontidae: iguanodons
family Indicatoridae: honey guides
family Indriidae: a family of Lemuroidea
family Irenidae: a family of birds of the suborder Oscines
family Istiophoridae: sailfishes; spearfishes; marlins
family Isuridae: in some classifications another name for the family Lamnidae
family Ixodidae: hard ticks
family Jassidae: family of small leafhoppers coextensive with the Cicadellidae and not distinguished from it in some classifications
family Kalotermitidae: primitive termites of warm regions
family Kasuwonidae: in some classifications considered a separate family comprising the oceanic bonitos
family Kinosternidae: mud turtles; musk turtles
family Kyphosidae: sea chubs
family Labridae: wrasses
family Lacertidae: Old World lizards
family Lactobacteriaceae: lactic acid bacteria and important pathogens; bacteria that ferment carbohydrates chiefly into lactic acid
family Laminariaceae: large family of marine brown algae including many economically important large kelps chiefly of northern waters
family Lamnidae: oceanic sharks
family Lampridae: opahs
family Lampyridae: fireflies
family Laniidae: shrikes
family Lanthanotidae: stout-bodied lizards
family Laricariidae: armored catfish
family Laridae: gull family: gulls and terns
family Lasiocampidae: tent caterpillars; eggars; lappet moths
family Latimeridae: extinct except for the coelacanth
family Leiopelmatidae: primitive New Zealand frogs
family Lemuridae: typical lemurs; of Madagascar
family Lepadidae: goose barnacles
family Lepismatidae: firebrats
family Lepisosteidae: comprises the genus Lepisosteus
family Leporidae: hares and rabbits
family Leptodactylidae: New World frogs; in some classifications essentially coextensive with the family Bufonidae
family Leptotyphlopidae: blind snakes
family Limacidae: slugs
family Limulidae: horseshoe crabs
family Liparididae: snailfishes
family Lithodidae: deep-sea crabs of cold waters
family Littorinidae: periwinkles
family Lobotidae: tripletails
family Locustidae: short-horned grasshoppers; true locusts
family Lophiidae: large-headed marine fishes comprising the anglers
family Lorisidae: slow-moving omnivorous nocturnal primates of tropical Asia; usually tailless
family Lucanidae: stag beetles
family Lutjanidae: snappers
family Luvaridae: louvars
family Lycaenidae: family of small usually brilliantly colored butterflies; males have short forelegs
family Lycosidae: wolf spiders
family Lygaeidae: lygaeid bugs
family Lymantriidae: tussock moths
family Machilidae: jumping bristletails
family Macropodidae: kangaroos; wallabies
family Macrorhamphosidae: bellows fishes
family Macrouridae: grenadiers
family Majidae: spider crabs
family Malacanthidae: short-headed marine fishes; often brightly colored
family Manidae: coextensive with the order Pholidota
family Manteidae: mantises
family Mantispidae: mantispids
family Mastodontidae: extinct family: mastodons
family Mastotermitidae: primitive termites
family Megachilidae: leaf-cutting and mason bees
family Megadermatidae: Old World false vampire bats
family Megalonychidae: mammal family consisting of the two-toed sloths
family Megalosauridae: megalosaurs
family Megapodiidae: megapodes
family Megatheriidae: extinct ground sloths
family Meleagrididae: turkeys and some extinct forms
family Meliphagidae: honey eaters
family Meloidae: blister beetles
family Membracidae: plant hoppers: treehoppers
family Menuridae: lyrebirds
family Meropidae: bee-eaters
family Micrococcaceae: spherical or elliptical usually aerobic eubacteria that produce yellow or orange or red pigment; includes toxin-producing forms as well as harmless commensals and saprophytes
family Microdesmidae: worm fish
family Mimidae: sometimes considered a subfamily of Troglodytidae: mockingbirds; catbirds; thrashers
family Mobulidae: large rays lacking venomous spines: mantas
family Molidae: ocean sunfishes
family Molossidae: mastiff bats; freetail bats
family Momotidae: a family of birds of the order Coraciiformes
family Monocanthidae: filefishes
family Monodontidae: narwhals
family Motacillidae: pipits and wagtails
family Mugilidae: grey mullets
family Mullidae: goatfishes or red mullets
family Muraenidae: marine eels
family Muridae: originally Old World rats now distributed worldwide; distinguished from the Cricetidae by typically lacking cheek pouches
family Muscicapidae: Old World (true) flycatchers
family Muscidae: two-winged flies especially the housefly
family Musophagidae: touracos
family Mustelidae: weasels; polecats; ferrets; minks; fishers; otters; badgers; skunks; wolverines; martens
family Mutillidae: a family of wasps
family Myacidae: soft-shell clams
family Mycetophylidae: fungus gnats
family Mycobacteriaceae: a family of bacteria
family Mycoplasmataceae: pleomorphic Gram-negative nonmotile microorganism similar to both viruses and bacteria; parasitic in mammals
family Myctophidae: deep-sea fishes comprising the lantern fishes
family Myliobatidae: eagle rays
family Mylodontidae: extinct South American edentates
family Myrmecophagidae: New World anteaters
family Myrmeleontidae: antlions
family Mysidae: small shrimp-like crustaceans
family Mytilidae: marine mussels
family Myxinidae: slime-producing marine animals: hagfishes
family Myxobacteriaceae: bacteria living mostly in soils and on dung
family Naticidae: moonshells
family Nautilidae: spiral-shelled cephalopods
family Nephropsidae: in some classifications coextensive with the Homaridae
family Nepidae: water scorpions
family Neritidae: neritids
family Nitrobacteriaceae: usually rod-shaped bacteria that oxidize ammonia or nitrites: nitrobacteria
family Noctuidae: cutworms; armyworms
family Nostocaceae: blue-green algae
family Notonectidae: aquatic carnivorous insects
family Notoryctidae: pouched moles
family Nummulitidae: a family of fossil protoctists
family Nymphalidae: large beautifully colored butterflies
family Ochotonidae: pikas and extinct forms
family Octopodidae: a family of Octopoda
family Odobenidae: walruses and extinct forms
family Odontaspididae: sand sharks; in some classifications coextensive with family Carcharhinidae
family Oedogoniaceae: filamentous green algae
family Ogcocephalidae: batfishes: sluggish bottom-dwelling spiny fishes
family Oniscidae: a family of Isopoda
family Ophidiidae: eellike marine fishes
family Ophiodontidae: fishes closely related to greenlings
family Opisthocomidae: comprising the hoatzins
family Opisthognathidae: jawfishes
family Orchestiidae: beach fleas
family Orectolobidae: nurse sharks and carpet sharks
family Oriolidae: Old World orioles
family Ornithorhynchidae: platypus
family Orycteropodidae: aardvarks
family Oscillatoriaceae: blue green algae
family Osmeridae: smelts
family Osteoglossidae: a family of large fishes that live in freshwater; includes bandfish and bonytongues
family Ostraciontidae: boxfishes
family Ostreidae: oysters
family Otariidae: eared seals: sea lions and fur seals
family Otididae: bustards
family Oxyuridae: pinworms
family Paguridae: hermit crabs
family Palaemonidae: prawns
family Palinuridae: spiny lobsters
family Pandionidae: ospreys
family Panorpidae: a family of insects of the order Mecoptera
family Paradisaeidae: birds of paradise
family Paridae: titmice and chickadees
family Parulidae: New World warblers
family Passeridae: true sparrows: Old world birds formerly considered weaverbirds
family Patellidae: marine limpets
family Pectinidae: scallops
family Pediculidae: true lice: human lice and related forms
family Pelecanidae: pelicans
family Pelecanoididae: diving petrels
family Pelobatidae: the amphibian family of spadefoot toads
family Pempheridae: sweepers
family Peneidae: tropical prawns
family Pennatulidae: sea pens
family Peramelidae: bandicoots
family Percidae: active freshwater fishes; true perches and pike perches
family Percophidae: percoid flatheads
family Peridiniidae: marine and freshwater dinoflagellates
family Peripatidae: a family of Onychophora
family Peripatopsidae: a family of Onychophora
family Petromyzontidae: lampreys
family Phaethontidae: tropicbirds
family Phalacrocoracidae: cormorants
family Phalangeridae: phalangers; koalas
family Phalangiidae: a family of Phalangida
family Phalaropidae: phalaropes
family Phasianidae: pheasants; quails; partridges
family Phasmatidae: stick insects
family Phocidae: earless seals
family Phoenicopteridae: flamingos
family Phoeniculidae: wood hoopoes
family Pholadidae: a family of Bivalvia
family Pholididae: a family of fish of suborder Blennioidea
family Phthiriidae: crab lice
family Phyllidae: leaf insects
family Phyllostomatidae: New World leaf-nosed bats
family Phylloxeridae: plant lice
family Physeteridae: sperm whales
family Physidae: freshwater snails
family Picidae: woodpeckers
family Pieridae: arthropod family including cabbage butterflies; sulphur butterflies
family Pinnotheridae: tiny soft-bodied crabs
family Pipidae: tongueless frogs
family Pipridae: manakins
family Pittidae: pittas
family Plasmodiidae: malaria parasites
family Plataleidae: spoonbills
family Platanistidae: river dolphins
family Platycephalidae: scorpaenoid flatheads
family Plethodontidae: small mostly terrestrial New World salamanders having neither lungs nor gills as adults
family Pleurobrachiidae: sea gooseberries
family Pleuronectidae: righteye flounders
family Ploceidae: weaverbirds
family Podargidae: frogmouths
family Podicipedidae: coextensive with the order Podicipitiformes
family Poeciliidae: topminnows
family Polynemidae: threadfins
family Polyodontidae: paddlefishes
family Polypedatidae: Old World tree frogs
family Pomacentridae: damselfishes
family Pomatomidae: food and game fishes related to pompanos
family Pongidae: usually considered as comprising orangutans; gorillas; chimpanzees; and sometimes gibbons
family Porcellionidae: sow bugs
family Portunidae: swimming crabs
family Potamogalidae: otter shrews
family Priacanthidae: small carnivorous percoid fishes found worldwide in tropical seas
family Pristidae: large primitive rays with elongated snouts
family Procaviidae: includes all recent members of the order Hyracoidea
family Procellariidae: petrels; fulmars; shearwaters
family Procyonidae: raccoons; coatis; cacomistles; kinkajous; and sometimes pandas
family Proteidae: mud puppies
family Prunellidae: hedge sparrow
family Pseudococcidae: scalelike insects: mealybugs
family Pseudomonodaceae: rod-shaped Gram-negative bacteria; include important plant and animal pathogens
family Psittacidae: coextensive with the order Psittaciformes
family Psocidae: a family of small soft-bodied insects that feed on decaying vegetation; related to booklice
family Psophiidae: trumpeters
family Psychodidae: very small two-winged flies with hairy wings that develop in moss and damp vegetable matter: sand flies
family Pteriidae: pearl oysters
family Pteroclididae: sandgrouses
family Pterodactylidae: a reptile family in the order Pterosauria
family Ptilonorhynchidae: bowerbirds
family Pulicidae: many common fleas attacking humans and domestic animals
family Pygopodidae: Australian and Tasmanian lizards
family Pyralididae: bee moths; corn borers; flour moths
family Pyrrhocoridae: firebugs
family Pythonidae: in some classifications a family separate from Boidae comprising Old World boas
family Rachycentridae: family of pelagic fishes containing solely the cobia
family Rajidae: bottom-dwelling tropical rays: skates
family Rallidae: rails; crakes; gallinules; coots
family Ramphastidae: toucans
family Ranidae: a family nearly cosmopolitan in distribution: true frogs
family Raphidae: extinct dodos and solitaires
family Raphidiidae: a family of arthropods of the suborder Megaloptera, including snakeflies
family Recurvirostridae: long-legged shorebirds
family Reduviidae: assassin bugs
family Regalecidae: ribbonfishes
family Rheidae: a family of birds coextensive with the order Rheiformes
family Rhincodontidae: small-toothed sharks comprising only one species
family Rhinobatidae: primitive rays with guitar-shaped bodies
family Rhinocerotidae: rhinoceroses
family Rhinolophidae: Old World leaf-nosed bats
family Rhinotermitidae: large widely distributed family of termites of temperate to tropical regions
family Rhizobiaceae: a small family of rod-shaped bacteria
family Rhodymeniaceae: a family of protoctist
family Rickettsiaceae: microorganism resembling bacteria inhabiting arthropod tissues but capable of causing disease in vertebrates
family Rynchopidae: coextensive with the genus Rynchops: skimmers
family Sagittariidae: secretary birds
family Salamandridae: salamanders
family Salmonidae: salmon and trout
family Salpidae: a small family of tunicates in the class Thaliacea
family Sarcoptidae: small whitish mites
family Saturniidae: important and widely distributed family of moths including some of the largest insects known
family Satyridae: a widely distributed family of butterflies common near the edges of woods
family Scarabaeidae: scarab or dung beetles
family Scaridae: parrotfishes
family Schistosomatidae: a family of Trematoda
family Schizophyceae: former terms for Cyanophyceae
family Sciaenidae: warm-water marine fishes including the drums and grunts and croakers and sea trout
family Sciaridae: fungus gnats
family Scincidae: skinks
family Sciuridae: a mammal family of true squirrels including: ground squirrels; marmots; chipmunks; flying squirrels; spermophiles
family Scolopacidae: sandpiper family: sandpipers; woodcocks; snipes; tattlers; curlews; godwits; dowitchers
family Scolytidae: large family of bark-boring or wood-boring short-beaked beetles; very destructive to forest and fruit trees
family Scomberesocidae: only sauries
family Scombridae: marine food fishes: mackerels; chub mackerels; tuna
family Scorpaenidae: scorpionfishes; rockfishes; lionfishes
family Scutigeridae: a family of Chilopoda
family Scyliorhinidae: small bottom-dwelling sharks
family Sepiidae: true cuttlefishes
family Serranidae: marine fishes: sea basses; sea perches; groupers; jewfish
family Sialidae: an arthropod family including: alderflies
family Sillaginidae: small family of small food fishes in shallow waters of the Pacific around Indonesia
family Siluridae: Old World catfishes
family Simuliidae: blackflies and sand flies
family Sirenidae: sirens
family Sisyridae: an arthropod family of the order Neuroptera that includes spongeflies
family Sittidae: nuthatches
family Soleidae: soles
family Solenidae: razor clams
family Soricidae: shrews
family Spalacidae: mole rats
family Sparidae: porgies; scups
family Sphecidae: mud daubers; some digger wasps
family Spheniscidae: comprising all existing penguins
family Sphingidae: hawkmoths
family Sphyraenidae: monotypic family of large active fishes of tropical and subtropical waters: barracuda
family Sphyrnidae: hammerhead sharks; bonnethead sharks
family Spirillaceae: rigid spirally curved elongate bacteria
family Spirochaetaceae: large coarsely spiral bacteria; free-living in fresh or salt water or commensal in bodies of oysters
family Spirulidae: coextensive with the genus Spirula; included in the order Belemnoidea in some older classifications
family Squalidae: dogfishes having a spine in each dorsal fin
family Squatinidae: bottom-dwelling ray-like sharks
family Squillidae: crustaceans that burrow in mud or under stones in shallow water along the seashore
family Staphylinidae: rove beetles
family Steatornithidae: oilbirds
family Stenopelmatidae: long-horned grasshoppers
family Stercorariidae: jaegers and skuas:
family Stichaeidae: pricklebacks
family Stizidae: cicada killers
family Streptomycetaceae: higher bacteria typically aerobic soil saprophytes
family Strigidae: a family of nocturnal birds of the order Strigiformes
family Stromateidae: butterfishes: harvest fishes; dollar fishes
family Strombidae: the family of conchs
family Struthionidae: tall terrestrial birds: ostriches
family Sturnidae: Old World starlings
family Suidae: pigs; hogs; boars
family Sulidae: gannets and boobies
family Sylviidae: in some classifications considered a subfamily (Sylviinae) of the family Muscicapidae: Old World (true) warblers; American kinglets and gnatcatchers
family Syngnathidae: pipefishes
family Synodontidae: soft-finned bottom-dwelling fishes
family Tabanidae: horseflies
family Tachinidae: parasites on other insects
family Tachyglossidae: echidnas
family Taeniidae: a family of Cestoda
family Talpidae: moles
family Tapiridae: tapirs and extinct related forms
family Tarsiidae: coextensive with the genus Tarsius: tarsiers
family Tayassuidae: peccaries
family Teiidae: whiptails; etc.
family Tenebrionidae: a family of arthropods including darkling beetles and mealworms
family Tenrecidae: tenrecs and extinct related forms
family Tenthredinidae: sawflies
family Terebellidae: marine burrowing or tube-forming polychete worms usually having long thick bodies
family Teredinidae: shipworms
family Termitidae: termites
family Testudinidae: land tortoises
family Tetranychidae: plant-feeding mites
family Tetraodontidae: puffers
family Tetraonidae: grouse
family Tettigoniidae: long-horned grasshoppers; katydids
family Theraphosidae: large tropical spiders; tarantulas
family Theridiidae: a family of comb-footed spiders
family Thiobacteriaceae: free-living coccoid to rod-shaped bacteria that derive energy from oxidizing sulfur or sulfur compounds
family Thraupidae: tanagers
family Threskiornithidae: ibises
family Thripidae: thrips
family Timaliidae: babblers
family Tinamidae: comprising the tinamous
family Tineidae: clothes moths
family Tingidae: lace bugs
family Tipulidae: crane flies
family Titanosauridae: herbivorous dinosaurs of the Cretaceous
family Todidae: a family of birds of the order Coraciiformes
family Torpedinidae: electric rays
family Tortricidae: leaf rollers and codling moths
family Toxotidae: archerfishes
family Trachipteridae: ribbonfishes
family Tragulidae: chevrotains
family Trephritidae: fruit flies; some leaf miners
family Treponemataceae: small spirochetes some parasitic or pathogenic
family Triakidae: small sharks with smooth skins and lacking spines on their dorsal fins
family Tribonemaceae: simple filamentous freshwater yellow-green algae
family Trichechidae: comprising only the manatees
family Trichiuridae: cutlassfishes
family Trichodontidae: two species of elongate compressed scaleless large-eyed fishes that live in sand or mud
family Tridacnidae: large marine hard-shell clams
family Triglidae: in some classifications restricted to the gurnards and subdivided into the subfamilies Triglinae (true sea robins) and Peristediinae (armored sea robins)
family Trionychidae: soft-shelled turtles
family Triopidae: a family of Notostraca
family Trochilidae: hummingbirds
family Troglodytidae: wrens
family Trogonidae: coextensive with the order Trogoniformes
family Trombiculidae: mites
family Trombidiidae: mites
family Tupaiidae: tree shrews; in some classifications tree shrews are considered prosimian primates
family Turdidae: thrushes; in some classifications considered a subfamily (Turdinae) of the family Muscicapidae
family Turnicidae: small Old World birds resembling but not related to true quail
family Tylenchidae: a family of Nematoda
family Typhlopidae: blind snakes
family Tytonidae: comprising only the barn owls
family Uintatheriidae: an extinct family of Dinocerata
family Ulvaceae: thin flat or tubular green algae
family Unionidae: freshwater mussels found worldwide
family Upupidae: hoopoes
family Uranoscopidae: stargazers
family Ursidae: bears and extinct related forms
family Varanidae: monitor lizards
family Veneridae: hard-shell clams
family Vespertilionidae: the majority of common bats of temperate regions of the world
family Vespidae: an arthropod family of the order Hymenoptera including: yellow jackets; hornets; mason wasps
family Viperidae: Old World vipers
family Vireonidae: small insectivorous American songbirds
family Viverrinae: genets; civets; mongooses
family Volvocaceae: unicellular or colonial biflagellate free-swimming flagellates
family Vombatidae: wombats
family Xantusiidae: night lizards
family Xenopodidae: in some classifications the family of the genus Xenopus which is otherwise included in the family Pipidae
family Xenosauridae: monotypic family of Mexican lizards
family Xiphiidae: comprising the common swordfishes
family Zapodidae: jumping mice
family Zeidae: a family of fish in the order Zeomorphi
family Zoarcidae: eelpouts
family Zygnemataceae: pond scums: common freshwater algae forming green slimy masses
fang: hollow or grooved tooth of a venomous snake; used to inject its poison
fang: canine tooth of a carnivorous animal; used to seize and tear its prey
fang: an appendage of insects that is capable of injecting venom; usually evolved from the legs
farm animal: any animals kept for use or profit
Fasciola hepatica: flatworm parasitic in liver and bile ducts of domestic animals and humans
Fasciolopsis buski: fluke that is parasitic on humans and swine; common in eastern Asia
fawn: a young deer
feather: the light horny waterproof structure forming the external covering of birds
feeder: an animal being fattened or suitable for fattening
feeder: an animal that feeds on a particular source of food
feist: a nervous belligerent little mongrel dog
felid: any of various lithe-bodied roundheaded fissiped mammals, many with retractile claws
Felis bengalensis: small spotted wildcat of southern Asia and Malaysia
Felis chaus: small Asiatic wildcat
Felis concolor: large American feline resembling a lion
Felis domesticus: any domesticated member of the genus Felis
Felis ocreata: widely distributed wildcat of Africa and Asia Minor
Felis pardalis: nocturnal wildcat of Central America and South America having a dark-spotted buff-brown coat
Felis serval: slender long-legged African wildcat having large untufted ears and tawny black-spotted coat
Felis silvestris: bushy-tailed wildcat of Europe that resembles the domestic cat and is regarded as the ancestor of the domestic cat
Felis tigrina: medium-sized wildcat of Central America and South America having a dark-striped coat
Felis wiedi: small spotted wildcat found from Texas to Brazil
Felis yagouaroundi: long-bodied long-tailed tropical American wildcat
female: an animal that produces gametes (ova) that can be fertilized by male gametes (spermatozoa)
female horse: female equine animal
female mammal: animals that nourish their young with milk
fence lizard: spiny lizard often seen basking on fences in the United States and northern Mexico
Fenusa pusilla: small black sawfly native to Europe but established in eastern United States; larvae mine the leaves of birches causing serious defoliation
ferret: domesticated albino variety of the European polecat bred for hunting rats and rabbits
ferret badger: small ferret-like badger of southeast Asia
fetlock: projection behind and above a horse's hoof
fetlock: the joint between the cannon bone and the pastern
fetter bone: the part between the fetlock and the hoof
fetus: an unborn or unhatched vertebrate in the later stages of development showing the main recognizable features of the mature animal
fictional animal: animals that exist only in fiction (usually in children's stories)
fiddler crab: burrowing crab of American coastal regions having one claw much enlarged in the male
field mouse: any nocturnal Old World mouse of the genus Apodemus inhabiting woods and fields and gardens
field mouse: any of various small mouselike rodents of the family Cricetidae (especially of genus Microtus) having a stout short-tailed body and inconspicuous ears and inhabiting fields or meadows
field spaniel: large usually black hunting and retrieving spaniel with a dense flat or slightly wavy coat; cross between cocker and Sussex spaniel
fig-bird: greenish-yellow Australian oriole feeding chiefly on figs and other fruits
fighting cock: a cock bred and trained for fighting
filaria: slender threadlike roundworms living in the blood and tissues of vertebrates; transmitted as larvae by biting insects
filefish: narrow flattened warm-water fishes with leathery skin and a long file-like dorsal spine
filly: a young female horse under the age of four
Filoviridae: a family of threadlike RNA viruses that cause diseases in humans and nonhuman primates (monkeys and chimpanzees)
filovirus: animal viruses belonging to the family Filoviridae
fin: organ of locomotion and balance in fishes and some other aquatic animals
finch: any of numerous small songbirds with short stout bills adapted for crushing seeds
fingerling: a young or small fish
finisher: an animal that wins in a contest of speed
fire ant: omnivorous ant of tropical and subtropical America that can inflict a painful sting
firebug: a true bug: brightly colored bug that can exude a stain
firefly: nocturnal beetle common in warm regions having luminescent abdominal organs
first stomach: the first compartment of the stomach of a ruminant; here food is collected and returned to the mouth as cud for chewing
fish: any of various mostly cold-blooded aquatic vertebrates usually having scales and breathing through gills
fish duck: large crested fish-eating diving duck having a slender hooked bill with serrated edges
fish family: any of various families of fish
fish fly: similar to but smaller than the dobsonfly; larvae are used as fishing bait
fish genus: any of various genus of fish
fish louse: a kind of copepod
fish scale: scale of the kind that covers the bodies of fish
fishbone: a bone of a fish
fissiped: terrestrial carnivores; having toes separated to the base: dogs; cats; bears; badgers; raccoons
Fissipedia: in some classifications considered a suborder of Carnivora
Fissurella apertura: marine limpet having a conical shell with an opening at the apex
flag: a conspicuously marked or shaped tail
flagellate: a usually nonphotosynthetic free-living protozoan with whiplike appendages; some are pathogens of humans and other animals
flagellated cell: any cell or one-celled organism equipped with a flagellum
flagellum: a lash-like appendage used for locomotion (e.g., in sperm cells and some bacteria and protozoa)
flame cell: organ of excretion in flatworms
flamingo: large pink to scarlet web-footed wading bird with down-bent bill; inhabits brackish lakes
flank: the side between ribs and hipbone
flat-coated retriever: an English breed having a shiny black or liver-colored coat; retrieves game from land or water
flatfish: any of several families of fishes having flattened bodies that swim along the sea floor on one side of the body with both eyes on the upper side
flathead: food fish of the Indonesian region of the Pacific; resembles gurnards
flathead: pallid bottom-dwelling flat-headed fish with large eyes and a duck-like snout
flatworm: parasitic or free-living worms having a flattened body
Flaviviridae: a family of arboviruses carried by arthropods
flavivirus: animal viruses belonging to the family Flaviviridae
flea: any wingless bloodsucking parasitic insect noted for ability to leap
flea beetle: any small leaf beetle having enlarged hind legs and capable of jumping
fledgeling: young bird that has just fledged or become capable of flying
fleece: outer coat of especially sheep and yaks
flicker: North American woodpecker
flight feather: any of the larger wing or tail feathers of a bird
flightless bird: flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches; cassowaries; emus; moas; rheas; kiwis; elephant birds
flipper: the flat broad limb of aquatic animals specialized for swimming
Florida smoothhound: found from the northern Gulf of Mexico to Brazil
Florida water rat: of Florida wetlands
flounder: any of various European and non-European marine flatfish
flour beetle: an insect that infests flour and stored grains
fluke: either of the two lobes of the tail of a cetacean
fluke: parasitic flatworms having external suckers for attaching to a host
fly: two-winged insects characterized by active flight
flycatching warbler: any of numerous American wood warblers that feed on insects caught on the wing
flying fish: tropical marine fishes having enlarged winglike fins used for brief gliding flight
flying fox: large bat with a head that resembles the head of a fox
flying mouse: tiny flying phalanger
flying opossum: nocturnal phalangers that move with gliding leaps using parachute-like folds of skin along the sides of the body
flying reptile: an extinct reptile of the Jurassic and Cretaceous having a bird-like beak and membranous wings supported by the very long fourth digit of each forelimb
foal: a young horse
food fish: any fish used for food by human beings
foot: any of various organs of locomotion or attachment in invertebrates
foram: marine microorganism having a calcareous shell with openings where pseudopods protrude
fore wing: either of the anterior pair of wings on an insect that has four wings
forefoot: a front foot of a quadruped
foreleg: the forelimb of a quadruped
forelimb: the front limb (or the homologous structure in other animals, such as a flipper or wing)
forelock: a lock of a horse's mane that grows forward between the ears
forepaw: front paw; analogous to the human hand
form genus: an artificial taxonomic category established on the basis of morphological resemblance for organisms of obscure true relationships especially fossil forms
Formica fusca: an ant frequently enslaved
Formica rufa: reddish-brown European ant typically living in anthills in woodlands
Formica sanguinea: slave-making ant widely distributed over the northern hemisphere
Fossa fossa: civet of Madagascar
fossorial foot: foot adapted for digging as in moles
fossorial mammal: a burrowing mammal having limbs adapted for digging
fox: alert carnivorous mammal with pointed muzzle and ears and a bushy tail; most are predators that do not hunt in packs
fox terrier: small lively black-and-white terriers formerly used to dig out foxes
foxhound: medium-sized glossy-coated hounds developed for hunting foxes
Francisella tularensis: the type species of the genus Francisella and the causal agent of tularemia in humans; can be used as a bioweapon
Frankliniella fusca: injurious to growing tobacco and peanuts
Fratercula arctica: common puffin of the northern Atlantic
Fratercula corniculata: northern Pacific puffin
freetail: small swift insectivorous bat with leathery ears and a long tail; common in warm regions
French bulldog: small stocky version of the bulldog having a sleek coat and square head
freshwater bass: North American food and game fish
freshwater clam: bivalve mollusk abundant in rivers of central United States
frigate bird: long-billed warm-water seabird with wide wingspan and forked tail
Fringilla coelebs: small European finch with a cheerful song
Fringilla montifringilla: Eurasian finch
fritillary: butterfly with brownish wings marked with black and silver
frogfish: fish having a frog-like mouth with a lure on the snout
froghopper: a variety of spittlebug
frogmouth: insectivorous bird of Australia and southeastern Asia having a wide frog-like mouth
fruit bat: large Old World bat of warm and tropical regions that feeds on fruit
fruit fly: any of numerous small insects whose larvae feed on fruits
fucoid: a fossilized cast or impression of algae of the order Fucales
fucoid: any of various algae of the family Fucaceae
fucus: any member of the genus Fucus
Fucus serratus: brown algae seaweed with serrated edges
Fucus vesiculosus: a common rockweed used in preparing kelp and as manure
Fulica americana: a coot found in North America
Fulmarus glacialis: heavy short-tailed oceanic bird of polar regions
Fundulus heteroclitus: silver-and-black killifish of saltwater marshes along the Atlantic coast of the United States
Fundulus majalis: black-barred fish of bays and coastal marshes of the Atlantic and Gulf Coast of the United States
fungus gnat: mosquito-like insect whose larvae feed on fungi or decaying vegetation
fungus gnat: minute blackish gregarious flies destructive to mushrooms and seedlings
fur: dense coat of fine silky hairs on mammals (e.g., cat or seal or weasel)
fur seal: eared seal of the southern hemisphere; the thick soft underfur is the source of sealskin
fur seal: an eared seal of the northern Pacific
furcula: a forked bone formed by the fusion of the clavicles of most birds
gadfly: any of various large flies that annoy livestock
gadoid: a soft-finned fish of the family Gadidae
Gadus macrocephalus: closely related to Atlantic cod
Gadus morhua: one of the world's most important commercial fishes
Galeocerdo cuvieri: large dangerous warm-water shark with striped or spotted body
Galeorhinus zyopterus: Pacific shark valued for its fins (used by Chinese in soup) and liver (rich in vitamin A)
Galictis vittatus: carnivore of Central America and South America resembling a weasel with a greyish-white back and dark underparts
gall gnat: fragile mosquito-like flies that produce galls on plants
Gallant Fox: thoroughbred that won the triple crown in 1930
Galleria mellonella: moth whose larvae live in and feed on bee honeycombs
gallfly: any of various insects that deposit their eggs in plants causing galls in which the larvae feed
gallina: small Asiatic wild bird; believed to be ancestral to domestic fowl
gallinacean: heavy-bodied largely ground-feeding domestic or game birds
Gallinago gallinago: common snipe of Eurasia and Africa
Gallinago gallinago delicata: American snipe
Gallinago media: Old World snipe larger and darker than the whole snipe
Gallinula chloropus: black gallinule that inhabits ponds and lakes
Gallinula chloropus cachinnans: North American dark bluish-grey gallinule
gallinule: any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens
Galloway: breed of hardy black chiefly beef cattle native to Scotland
Gallus gallus: a jungle fowl of southeastern Asia that is considered ancestral to the domestic fowl
Gallus gallus: a domestic fowl bred for flesh or eggs; believed to have been developed from the red jungle fowl
Gambusia affinis: silvery topminnow with rows of black spots of tropical North America and West Indies; important in mosquito control
game: animal hunted for food or sport
game bird: any bird (as grouse or pheasant) that is hunted for sport
game fish: any fish providing sport for the angler
game fowl: any of several breeds reared for cockfighting
gander: mature male goose
gannet: large heavily built seabird with a long stout bill noted for its plunging dives for fish
ganoid: primitive fishes having thick bony scales with a shiny covering
ganoin: shiny substance that resemble enamel and is secreted by the corium of certain fishes (especially ganoid fishes) and composes the outer layer of their scales
garden snail: any of several inedible snails of the genus Helix; often destructive pests
garter snake: any of numerous nonvenomous longitudinally-striped viviparous North American and Central American snakes
gaskin: lower part of a horse's thigh between the hock and the stifle
Gasterophilus intestinalis: parasitic chiefly on horses
Gasterosteus: type genus of the family Gasterosteidae
Gasterosteus aculeatus: of rivers and coastal regions
Gasterosteus pungitius: confined to rivers
gastric mill: thick-walled muscular pouch below the crop in many birds and reptiles for grinding food
Gastrophryne carolinensis: small toad of southeastern United States
Gastrophryne olivacea: small secretive toad with smooth tough skin of central and western North America
gastropod: a class of mollusks typically having a one-piece coiled shell and flattened muscular foot with a head bearing stalked eyes
gastrula: double-walled stage of the embryo resulting from invagination of the blastula; the outer layer of cells is the ectoderm and the inner layer differentiates into the mesoderm and endoderm
Gavialis gangeticus: large fish-eating Indian crocodilian with a long slender snout
gaviiform seabird: seabirds of the order Gaviiformes
Gazella subgutturosa: a kind of gazelle
gazelle: small swift graceful antelope of Africa and Asia having lustrous eyes
gecko: any of various small chiefly tropical and usually nocturnal insectivorous terrestrial lizards typically with immovable eyelids; completely harmless
gee-gee: a word for horse used by children or in adult slang
gelding: castrated male horse
Gelechia gossypiella: small brown moth whose larvae bore into flowers and bolls of cotton
Gelechia gossypiella: larvae of a gelechiid moth introduced from Asia; feeds on the seeds of cotton bolls
gelechiid: small slender-winged moths whose larvae are agricultural pests
gempylid: snake mackerels; elongated marine fishes with oily flesh; resembles mackerels; found worldwide
Gempylus serpens: predatory tropical fishes with jutting jaws and strong teeth
Genetta genetta: agile Old World viverrine having a spotted coat and long ringed tail
genus Abramis: European fishes
genus Abrocoma: abrocomes
genus Abudefduf: damsel fishes
genus Acanthisitta: a genus of Xenicidae
genus Acanthocybium: wahoos
genus Acanthophis: Australian elapid snakes
genus Acanthoscelides: a genus of Bruchidae
genus Acanthurus: type genus of the Acanthuridae: doctorfishes
genus Acarus: any of several mites of the order Acarina
genus Accipiter: type genus of the family Accipitridae
genus Acherontia: death's-head moth
genus Acheta: common house and field crickets
genus Achoerodus: a genus of Labridae
genus Acinonyx: cheetahs
genus Acipenser: type genus of the Acipenseridae: sturgeons
genus Acridotheres: mynas
genus Acris: cricket frogs
genus Acrobates: a genus of Phalangeridae
genus Acrocephalus: a genus of Sylviidae
genus Acropora: coelenterate genus of order Madreporaria, including staghorn corals
genus Actias: luna moths
genus Actinia: a genus of sea anemone common in rock pools
genus Actinomyces: type genus of the family Actinomycetaceae
genus Actitis: a genus of Scolopacidae
genus Adalia: genus of ladybugs
genus Addax: genus of antelopes of northern African deserts
genus Adelges: type genus of the Adelgidae: plant lice
genus Adenota: African antelopes: puku
genus Aedes: yellow-fever mosquitos
genus Aegypius: a genus of Accipitridae
genus Aegyptopithecus: a genus of Hominoidea
genus Aepyceros: African antelopes: impalas
genus Aepyornis: type genus of the Aepyornidae: elephant birds
genus Aerobacter: aerobic bacteria widely distributed in nature
genus Aetobatus: a genus of Myliobatidae
genus Afropavo: Congo peafowl
genus Agama: type genus of the Agamidae
genus Agapornis: a genus of Psittacidae
genus Agelaius: red-winged blackbirds
genus Agkistrodon: copperheads
genus Agonus: type genus of the Agonidae
genus Agriocharis: a genus of birds of the family Meleagrididae including the ocellated turkey
genus Agrobacterium: small motile bacterial rods that can reduce nitrates and cause galls on plant stems
genus Ailuropoda: only the giant panda: in some classifications considered a genus of the separate family Ailuropodidae
genus Ailurus: lesser pandas
genus Aix: wood duck and mandarin duck
genus Ajaia: a genus of Platalea
genus Alauda: type genus of the Alaudidae: skylarks
genus Albula: type and sole genus of the family Albulidae
genus Alca: type genus of the Alcidae comprising solely the razorbill
genus Alcedo: type genus of the Alcedinidae
genus Alcelaphus: African antelopes: hartebeests
genus Alces: elk or moose
genus Alectis: a genus of Carangidae
genus Alectoris: a genus of Perdicidae
genus Alectura: brush turkeys
genus Alepisaurus: slender scaleless predaceous tropical deep-sea fishes
genus Aleyrodes: type genus of the Aleyrodidae
genus Algeripithecus: an extinct genus of Hominoidea
genus Alligator: type genus of the Alligatoridae
genus Alopex: arctic foxes
genus Alopius: type genus of the family Alopiidae; in some classifications considered a genus of the family Lamnidae
genus Alosa: shad
genus Alouatta: howler monkeys
genus Alsophila: geometrid moths
genus Alytes: midwife toads
genus Amazona: a genus of Psittacidae
genus Ambloplites: a genus of Centrarchidae
genus Amblyrhynchus: marine iguanas
genus Ambystoma: type genus of the Ambystomatidae
genus Ameiurus: type genus of the Ameiuridae: bullhead catfishes
genus Amia: type genus of the Amiidae
genus Ammodytes: type genus of the Ammodytidae
genus Ammotragus: genus of wild sheep
genus Amoeba: protozoan inhabiting moist soils or bottom vegetation in fresh or salt water
genus Amphibolips: cynipid gall wasps, especially causing oak-apple galls
genus Amphioxus: type genus of the Amphioxidae
genus Amphiprion: damsel fishes
genus Amphisbaenia: type genus of the Amphisbaenidae
genus Amphiuma: congo snakes
genus Anabas: the type genus of the family Anabantidae; small fish that resemble perch
genus Anabrus: a genus of Tettigoniidae
genus Anagasta: moth whose larvae are flour moths
genus Anarhichas: type genus of the Anarhichadidae
genus Anas: type genus of the Anatidae: freshwater ducks
genus Anasa: squash bugs
genus Anastomus: openbills
genus Anatotitan: genus of large duck-billed dinosaurs; late Cretaceous
genus Ancylus: type genus of the family Ancylidae: river limpet
genus Andrena: a solitary burrowing short-tongued bee
genus Andricus: cynipid gall wasps, chiefly affecting oaks
genus Aneides: climbing salamanders
genus Anguilla: type genus of the Anguillidae: eels
genus Anguillula: a genus of Cephalobidae
genus Anguis: type genus of the Anguidae: blindworms
genus Anhima: type genus of the Anhimidae; horned screamers
genus Anhinga: type genus of the Anhingidae
genus Anisotremus: a genus of Haemulidae
genus Ankylosaurus: armored herbivorous dinosaurs of the Cretaceous
genus Anoa: a genus of mammals of the family Bovidae
genus Anodonta: thin-shelled freshwater mussels
genus Anolis: New World chameleons
genus Anomala: genus of beetles whose grubs feed mainly on roots of plants; includes several pests of cultivated grasses
genus Anomalops: type genus of the family Anomalopidae
genus Anomalopteryx: small moas
genus Anomia: type genus of the family Anomiidae: saddle oysters
genus Anopheles: malaria mosquitoes; distinguished by the adult's head-downward stance and absence of breathing tubes in the larvae
genus Anser: typical geese
genus Antedon: a genus of echinoderms of the family Antedonidae
genus Antheraea: large moths whose larvae produce silk of high quality
genus Anthidium: potter bees
genus Anthonomus: weevils destructive of cultivated plants
genus Anthus: pipits
genus Antidorcas: springboks
genus Antigonia: a genus of fish in the family Caproidae
genus Antilocapra: type and sole genus of the Antilocapridae comprising one species
genus Antilope: blackbucks
genus Antrodemus: carnivorous dinosaur of North America; late Jurassic
genus Antrozous: a genus of Vespertilionidae
genus Aotus: douroucoulis
genus Apatura: large Old World butterflies
genus Aphis: type genus of the Aphididae: injurious to fruit trees and vegetables
genus Aphriza: a genus of Scolopacidae
genus Aphrophora: a genus of Cercopidae
genus Apis: type genus of the Apidae: honeybees
genus Aplodontia: type genus of the Aplodontiidae: comprising the mountain beavers
genus Aplysia: type genus of the family Aplysiidae
genus Apodemus: Old World field mice
genus Apogon: type genus of the Apogonidae
genus Appendicularia: a genus of chordates in the class Larvacea
genus Aptenodytes: large penguins
genus Apteryx: type genus of the Apterygidae: kiwis
genus Apus: type genus
genus Aquila: a genus of Accipitridae
genus Ara: macaws
genus Aramus: genus of large brown long-billed wading birds found in warm swampy regions of the western hemisphere: courlan; limpkin
genus Araneus: a genus of orb-weaving spiders including common garden spiders and barn spiders
genus Arca: type genus of the family Arcidae: ark shells and blood clams
genus Arcella: type genus of the Arcellidae
genus Archaeopteryx: a genus of fossil birds
genus Archaeornis: a genus of fossil bird
genus Archidiskidon: a genus of Elephantidae
genus Archilochus: a genus of Trochilidae
genus Architeuthis: giant squid
genus Archosargus: a genus of Sparidae
genus Arctictis: binturongs
genus Arctocebus: a genus of Lorisidae
genus Arctocephalus: fur seals
genus Arctonyx: a genus of Mustelidae
genus Ardea: type genus of the Ardeidae: large New and Old World herons
genus Arenaria: turnstones
genus Argentina: type genus of the Argentinidae: argentines
genus Argentinosaurus: enormous dinosaur of the middle Cretaceous found in Argentina
genus Argiope: the type genus of Argiopidae; small genus of orb-weaving spiders
genus Argonauta: type genus of the family Argonautidae: paper nautilus
genus Argusianus: argus pheasants
genus Argynnis: fritillaries
genus Argyrotaenia: orange tortrix
genus Arilus: a genus of Reduviidae
genus Ariomma: a genus of Stromateidae
genus Arius: type genus of the Ariidae: sea catfishes
genus Arizona: glossy snake
genus Armadillidium: type genus of the Armadillidiidae
genus Artamus: type genus of the Artamidae
genus Arvicola: in some classifications considered synonymous with Microtus
genus Ascaphus: type genus of the Ascaphidae; in some classifications included in the family Leiopelmatidae
genus Ascaridia: roundworm having a preanal sucker
genus Ascaris: type genus of the family Ascaridae: roundworms with a three-lipped mouth
genus Ascophyllum: brown algae distinguished by compressed or inflated branchlets along the axis
genus Asio: a genus of European owls
genus Aspidelaps: African coral snakes
genus Aspidiotus: a genus of Diaspididae
genus Aspidophoroides: alligatorfishes
genus Astacus: type genus of the family Astacidae; Old World crayfish
genus Astrophyton: includes many of the basket stars
genus Astropogon: a genus of fish of the family Apogonidae
genus Ateles: spider monkeys
genus Athene: a genus of Strigidae
genus Atherinopsis: a genus of Atherinidae
genus Atherurus: a genus of Hystricidae
genus Atrichornis: type genus of the Atrichornithidae
genus Atticus: atlas moth
genus Aulacorhyncus: a genus of Ramphastidae
genus Aulostomus: type genus of the Aulostomidae
genus Auriparus: a genus of Paridae
genus Australopithecus: extinct genus of African hominid
genus Automeris: io moth
genus Avahi: a genus of Indriidae
genus Aythya: canvasback; redhead; pochard; etc.
genus Babyrousa: a genus of Suidae
genus Bacillus: type genus of the Bacillaceae; includes many saprophytes important in decay of organic matter and a number of parasites
genus Bacteroides: type genus of Bacteroidaceae; genus of Gram-negative rodlike anaerobic bacteria producing no endospores and no pigment and living in the gut of man and animals
genus Baiomys: pygmy mice
genus Bairdiella: drumfish
genus Balaena: type genus of the Balaenidae: Greenland whales
genus Balaeniceps: type genus of the Balaenicipitidae: shoebills
genus Balaenoptera: type genus of the Balaenopteridae
genus Balanus: type genus of the family Balanidae
genus Balistes: type genus of the Balistidae
genus Bankia: giant shipworms
genus Barosaurus: huge quadrupedal herbivorous dinosaur; late Jurassic
genus Bartramia: a genus of Scolopacidae
genus Basiliscus: a reptile genus of Iguanidae
genus Bassariscus: cacomistles
genus Bathyergus: mole rats
genus Batrachoseps: slender salamanders
genus Bemisia: sweet-potato whitefly
genus Beroe: coextensive with the class Nuda
genus Bettongia: jerboa kangaroo
genus Bibos: wild ox
genus Bison: sometimes considered a subgenus of genus Bos: American buffalo
genus Bitis: a genus of Viperidae
genus Blaberus: giant cockroaches
genus Blarina: shrews
genus Blatta: type genus of the Blattidae: cockroaches infesting buildings worldwide
genus Blattella: small cockroaches
genus Blennius: type genus of the Blenniidae
genus Blissus: chinch bugs
genus Bombina: fire-bellied toads
genus Bombus: bumblebees
genus Bombyx: type genus of the Bombycidae: Chinese silkworm moth
genus Bonasa: ruffed grouse
genus Borrelia: small flexible parasitic spirochetes having three to five wavy spirals
genus Bos: wild and domestic cattle; in some classifications placed in the subfamily Bovinae or tribe Bovini
genus Boselaphus: Indian antelopes: nilgais
genus Botaurus: bitterns
genus Bothrops: fer-de-lance
genus Brachinus: bombardier beetles
genus Bradypus: type genus of the Bradypodidae: three-toed sloths
genus Brama: type genus of the Bramidae
genus Branchiobdella: type genus of the Branchiobdellidae: a small worm that lives on the gills or surface of a crayfish attached by a sucker
genus Branta: wild geese
genus Brevoortia: menhaden
genus Brontosaurus: large quadrupedal herbivorous dinosaurs with very long neck and tail; late Jurassic
genus Browmius: cusk
genus Bruchus: type genus of the Bruchidae
genus Bubalus: in some classification systems included in genus Bos; water buffaloes
genus Bubo: a genus of Strigidae
genus Bubulcus: small white egrets
genus Bucephala: buffleheads and goldeneyes
genus Buceros: type genus of the family Bucerotidae
genus Budorcas: gnu goats
genus Bufo: type genus of the Bufonidae; common toads of New and Old Worlds
genus Bungarus: kraits
genus Burhinus: type genus of the Burhinidae: stone curlews
genus Burmeisteria: a genus of Dasypodidae
genus Buteo: broad-winged soaring hawks
genus Cabassous: solely the tatouay
genus Cacajao: uakaris
genus Cacatua: a genus of Psittacidae
genus Cacicus: a genus of tropical American orioles
genus Cadra: a genus of Pyralidae
genus Caenolestes: type genus of the family Caenolestidae
genus Caiman: caimans
genus Cairina: a genus of Anatidae
genus Calamus: a genus of Sparidae
genus Calidris: a genus of Scolopacidae
genus Callicebus: titis
genus Callimorpha: cinnabar moths
genus Callinectes: New World blue crabs
genus Calliophis: Asian coral snakes
genus Calliphora: type genus of the Calliphoridae: blowflies
genus Callisaurus: zebra-tailed lizard
genus Callithrix: type genus of the Callithricidae: true marmosets
genus Callorhinus: fur seals
genus Calosoma: genus of large predaceous ground beetles that feed on injurious caterpillars
genus Calymmatobacterium: a genus of bacterial rods containing only the one species that causes granuloma inguinale
genus Cambarus: a genus of Astacidae
genus Camelus: type genus of the Camelidae: camels
genus Campephilus: a genus of Picidae
genus Camponotus: carpenter ants
genus Campylorhynchus: alternative classifications for the cactus wrens
genus Canachites: spruce grouse
genus Cancer: type genus of the family Cancridae
genus Canis: type genus of the Canidae: domestic and wild dogs; wolves; jackals
genus Capra: goats
genus Caprella: skeleton shrimp
genus Capreolus: roe deer
genus Capricornis: serows
genus Caprimulgus: type genus of the Caprimulgidae
genus Capros: a genus of fish in the family Caproidae
genus Caranx: type genus of the Carangidae
genus Carassius: goldfish
genus Carcharhinus: type genus of the Carcharhinidae
genus Carcharias: type and sole genus of Carchariidae: sand sharks
genus Carcharodon: man-eating sharks
genus Cardium: type genus of the family Cardiidae: cockles
genus Carduelis: in some classifications considered the type genus of a subfamily Carduelinae of the family Fringillidae: goldfinches; siskins; redpolls; linnets
genus Caretta: loggerhead turtles
genus Cariama: the type genus of the Cariamidae comprising only the crested cariama
genus Carphophis: thunder snake
genus Carpocapsa: codling moths
genus Carpodacus: house finches and purple finches
genus Casmerodius: a white egrets
genus Castor: type genus of the Castoridae: beavers
genus Castoroides: extinct beavers of the Pleistocene; of eastern and southern United States
genus Casuarius: type and sole genus of the Casuaridae: cassowaries
genus Catacala: moths whose larvae are cutworms: underwings
genus Catharacta: skuas
genus Cathartes: type genus of the Cathartidae: turkey vultures
genus Catoptrophorus: willet
genus Catostomus: type genus of the family Catostomidae
genus Cavia: type genus of the Caviidae: guinea pigs
genus Cebuella: pygmy marmosets
genus Cebus: type genus of the Cebidae
genus Centrocercus: sage grouse
genus Centropomus: type genus of the Centropomidae: snooks
genus Centropristis: sea basses
genus Centropus: a genus of Cuculidae
genus Cephalopterus: a genus of Cotingidae
genus Cepphus: a genus of birds including: guillemots
genus Cerapteryx: antler moths
genus Cerastes: horned vipers
genus Ceratitis: Mediterranean fruit flies
genus Ceratodus: type genus of the Ceratodontidae: extinct genus of lungfishes
genus Ceratopogon: type genus of the Ceratopogonidae
genus Ceratosaurus: primitive saurischian carnivorous dinosaurs
genus Ceratotherium: African genus
genus Cercocebus: mangabeys
genus Cercopithecus: type genus of the Cercopithecidae: guenons
genus Certhia: type genus of the Certhiidae
genus Cervus: the type genus of the Cervidae
genus Ceryle: a genus of birds of the family Alcedinidae
genus Cestum: Venus's girdle
genus Cetonia: a genus of Cetoniidae
genus Cetorhinus: comprising only the basking sharks; in some classifications considered the type genus of a separate family Cetorhinidae
genus Chaenopsis: a genus of fish of the family Clinidae including pikeblennies
genus Chaetodipterus: a genus of Ephippidae
genus Chaetodon: type genus of the Chaetodontidae
genus Chalcis: type genus of the Chalcididae
genus Chalcostigma: thornbills
genus Chamaea: a genus of Paridae
genus Chamaeleon: type genus of the Chamaeleontidae
genus Chara: green algae common in freshwater lakes of limestone districts
genus Charadrius: type genus of the Charadriidae: plovers
genus Charina: boas of western North America
genus Charronia: a genus of Mustelidae
genus Chateura: a genus of Apodidae
genus Chauna: crested screamers
genus Chelifer: a genus of Chelonethida
genus Chelonia: green turtles
genus Chelydra: snapping turtles
genus Chilomastix: flagellates parasitic in intestines of vertebrates including humans
genus Chilomeniscus: sand snakes
genus Chilomycterus: burrfishes
genus Chimaera: type genus of the Chimaeridae
genus Chinchilla: type genus of the Chinchillidae
genus Chirocephalus: fairy shrimp; brine shrimp
genus Chironomus: type genus of the Chironomidae
genus Chiton: a genus of Polyplacophora
genus Chlamydera: a genus of Ptilonorhynchidae
genus Chlamydia: type genus of the family Chlamydiaceae: disease-causing parasites
genus Chlamydomonas: type genus of the Chlamydomonadaceae; solitary doubly-flagellated plant-like algae common in fresh water and damp soil; multiply freely; often a pest around filtration plants
genus Chlamydosaurus: frilled lizards
genus Chlamyphorus: pichiciago
genus Chlorella: nonmotile unicellular green algae potentially important as source of high-grade protein and B-complex vitamins
genus Chlorococcum: type genus of Chlorococcales; unicellular green algae occurring singly or in a layer on soil or damp rock
genus Chlorophis: African green snakes
genus Chlorophoneus: a genus of Malaconotinae
genus Chlorura: towhees
genus Choeronycteris: a genus of Phyllostomatidae
genus Choloepus: a genus of Megalonychidae consisting of the two-toed sloth
genus Chondrus: a genus of protoctist
genus Chordeiles: a genus of Caprimulgidae
genus Choriotis: Australian bustard
genus Chorizagrotis: moths whose larvae are army cutworms
genus Chronoperates: a reptile genus of Therapsida
genus Chrysaora: a genus of Scyphozoa
genus Chrysemys: painted turtles
genus Chrysochloris: type genus of the Chrysochloridae
genus Chrysolophus: golden pheasants
genus Chrysophrys: Australian snapper
genus Chunga: a genus of Cariamidae
genus Cicada: type genus of the Cicadidae: cicadas
genus Ciconia: type genus of the Ciconiidae: European storks
genus Cimex: type genus of the Cimicidae: bedbugs
genus Cinclus: type genus of the family Cinclidae
genus Circaetus: harrier eagles
genus Circus: a genus of haws comprising the harriers
genus Cistothorus: marsh wrens
genus Citharichthys: a genus of Bothidae
genus Cladorhyncus: one of two genera of stilts; similar to avocets but with straight bills
genus Clangula: a genus of ducks
genus Clethrionomys: a genus of Cricetidae
genus Clostridium: anaerobic or micro-aerophilic rod-shaped or spindle-shaped saprophytes; nearly cosmopolitan in soil, animal intestines, and dung
genus Clupea: type genus of the Clupeidae: typical herrings
genus Cnemidophorus: whiptails
genus Coccothraustes: large finches
genus Coccus: type genus of the Coccidae
genus Coccyzus: a genus of Cuculidae
genus Cochlearius: boatbills
genus Coelophysis: late Triassic carnivorous saurischian dinosaurs
genus Coereba: type genus of the Coerebidae
genus Colaptes: a genus of Picidae
genus Coleonyx: banded geckos
genus Colinus: New World quail: the bobwhites
genus Collocalia: a genus of Apodidae
genus Colobus: a genus of Cercopithecidae
genus Coluber: racers
genus Columba: type genus of the Columbidae: typical pigeons
genus Comatula: former usage synonymous with Antedon
genus Compsognathus: a reptile genus of Theropoda
genus Condylura: star-nosed moles
genus Conepatus: a genus of Mustelidae
genus Conilurus: jerboa rats
genus Connochaetes: African antelopes: gnus
genus Contopus: pewees
genus Conuropsis: a genus of Psittacidae
genus Coracias: type genus of the Coraciidae
genus Coragyps: a genus of Cathartidae
genus Cordylus: type genus of the Cordylidae; spiny lizards somewhat resembling tiny crocodiles
genus Coregonus: type genus of the Coregonidae: whitefishes
genus Corixa: type genus of the Corixidae: boat bugs
genus Corvus: type genus of the Corvidae: crows and ravens
genus Corydalis: type genus of the Corydalidae
genus Corynebacterium: the type genus of the family Corynebacteriaceae which is widely distributed in nature; the best known are parasites and pathogens of humans and domestic animals
genus Corythosaurus: genus of duck-billed dinosaurs of late Cretaceous
genus Coscoroba: a genus of Anatidae
genus Cosmocampus: a genus of fish in the family Syngnathidae
genus Costia: a genus of flagellate protoctist
genus Cotinga: type genus of the Cotingidae: cotingas
genus Cottus: type genus of the Cottidae: sculpins
genus Coturnix: Old World quail
genus Cracticus: type genus of the Cracticidae: Australian butcherbirds
genus Crangon: type genus of the family Crangonidae
genus Crassostrea: Virginia oysters
genus Crax: type genus of the Cracidae: curassows
genus Crex: corncrakes
genus Cricetus: type genus of the Cricetidae: Old World hamsters
genus Crocethia: a genus of Scolopacidae
genus Crocodilus: type genus of the Crocodylidae
genus Crocuta: a genus of Hyaenidae
genus Crotalus: large rattlesnakes; seldom bite unless startled or pursuing prey
genus Crotaphytus: collared lizards
genus Crotophaga: ani
genus Cryptacanthodes: a genus of Stichaeidae
genus Cryptobranchus: type genus of the Cryptobranchidae
genus Cryptocercus: cockroaches
genus Cryptoprocta: large primitive cat-like carnivores inhabiting forests of Madagascar
genus Cryptotermes: genus of dry wood termites; cosmopolitan in distribution; sometimes considered a subgenus of Kalotermes
genus Cryptotis: least shrews
genus Ctenocephalides: an arthropod genus of fleas
genus Ctenocephalus: a former usage synonymous with Ctenocephalides
genus Cuculus: type genus of the Cuculidae
genus Culex: type genus of the Culicidae: widespread genus of mosquitoes distinguished by holding the body parallel to the resting surface
genus Cuniculus: pacas
genus Cuon: Asiatic wild dog
genus Cursorius: coursers
genus Cuterebra: type genus of the Cuterebridae
genus Cyamus: whale lice
genus Cyanocitta: New World jays
genus Cyclopes: only the silky anteater
genus Cyclops: copepod water fleas
genus Cyclopterus: type genus of the Cyclopteridae: lumpfishes
genus Cygnus: a genus of Anatidae
genus Cynips: type genus of the Cynipidae: gall wasps
genus Cynocephalus: type genus of the family Cynocephalidae
genus Cynomys: prairie dogs
genus Cynopterus: a genus of Megachiroptera
genus Cynoscion: sea trout
genus Cypraea: type genus of the family Cypraeidae: the typical cowries
genus Cyprinus: type genus of the family Cyprinidae: carp
genus Cystophora: hooded seals
genus Dacelo: Australasian kingfishers
genus Dactylopius: type genus of the Dactylopiidae
genus Dactylopterus: a genus of Dactylopteridae
genus Dama: fallow deer
genus Damaliscus: African antelopes: sassabies
genus Danaus: type genus of the Danaidae: monarch butterflies
genus Daphnia: water fleas
genus Dasyatis: type genus of the Dasyatidae
genus Dasyprocta: type genus of the Dasyproctidae: agoutis
genus Dasypus: type genus of the Dasypodidae
genus Dasyurus: type genus of the family Dasyuridae: native cats
genus Daubentonia: type genus; coextensive with the family Daubentoniidae
genus Decapterus: scads especially mackerel scad; cosmopolitan in distribution
genus Deinocheirus: a reptile genus of Ornithomimida
genus Deinonychus: advanced bipedal carnivorous dinosaur
genus Delichon: a genus of Hirundinidae
genus Delphinapterus: white whale
genus Delphinus: type genus of the Delphinidae
genus Dendroaspis: mambas
genus Dendrocolaptes: type genus of the Dendrocolaptidae
genus Dendroctonus: genus of small bark beetles destructive especially to mature conifers
genus Dendroica: a genus of Parulidae
genus Dendrolagus: tree wallabies
genus Denisonia: copperheads
genus Dermacentor: vectors of important diseases of man and animals
genus Dermatobia: larvae live under the skin of domestic mammals and humans
genus Dermochelys: type genus of the Dermochelyidae: leatherback turtles
genus Desmidium: a genus of protoctist
genus Desmodus: type genus of the Desmodontidae: vampire bats
genus Desmograthus: an amphibian genus of Plethodontidae
genus Diadophis: a genus of reptiles of the family Colubridae including ringneck snakes
genus Dialeurodes: a genus of Aleyrodidae
genus Diapheromera: a genus of Phasmidae
genus Dicamptodon: type genus of the Dicamptodontidae
genus Diceros: most common species in Africa
genus Dicrostonyx: pied lemmings
genus Didelphis: type genus of the family Didelphidae
genus Difflugia: genus of protozoans related to ameba
genus Dimetrodon: a reptile genus of Pelycosauria
genus Dinornis: type genus of the Dinornithidae: large moas
genus Diodon: type genus of the Diodontidae
genus Diomedea: type of the Diomedeidae
genus Diphylla: vampire bats
genus Diplococcus: a genus of bacteria
genus Diplodocus: a reptile genus of the suborder Sauropoda
genus Dipodomys: kangaroo rats
genus Dipsosaurus: desert iguanas
genus Dipus: type genus of the Dipodidae; typical jerboas having three toes on each hind foot
genus Dolichonyx: bobolinks
genus Dolichotis: maras
genus Doliolum: type genus of the Doliolidae
genus Draco: a reptile genus known as flying dragons or flying lizards
genus Dracunculus: type genus of the family Dracunculidae
genus Dreissena: zebra mussels
genus Drepanis: a genus of Drepanididae
genus Dromaius: a genus of birds in the order Casuariiformes
genus Drosophila: a genus of Drosophilidae
genus Drymarchon: a genus of Colubridae
genus Dryopithecus: genus of Old World hominoids; Miocene and Pliocene
genus Dugong: type genus of the Dugongidae comprising only the dugongs
genus Dumetella: catbirds
genus Dusicyon: crab-eating dog
genus Dysdercus: a genus of slender long-legged bugs that feed on the developing seeds of cotton and stain it
genus Eacles: imperial moths
genus Echeneis: type genus of the Echeneididae: typical remoras
genus Echidnophaga: a genus of Siphonaptera
genus Echinococcus: tapeworms
genus Ectopistes: a genus of Columbidae
genus Edaphosaurus: type genus of the Edaphosauridae
genus Edmontosaurus: duck-billed dinosaurs of Canada
genus Egretta: small Old and New World herons
genus Eimeria: type genus of the family Eimeriidae; includes serious pathogens
genus Eira: a genus of Mustelidae
genus Elagatis: a genus of Carangidae
genus Elanoides: a genus of kites
genus Elanus: a genus of small kites of both Old and New Worlds
genus Elaphe: North American rat snakes
genus Elaphurus: a genus of Cervidae
genus Electrophorus: type genus of the family Electrophoridae; electric eels
genus Elephas: type genus of the family Elephantidae
genus Eleutherodactylus: completely terrestrial robber frogs
genus Eliomys: lerots
genus Elops: type genus of the Elopidae: tenpounder
genus Emberiza: Old World buntings
genus Endamoeba: the type genus of the family Endamoebidae
genus Engraulis: type genus of the family Engraulidae
genus Enhydra: sea otters
genus Ensis: razor clams
genus Enterobius: pinworms
genus Eoraptor: primitive theropod found in Argentina; early Triassic
genus Ephestia: small moths whose larvae spin silken tunnels and feed on stored food products
genus Ephippiorhynchus: saddlebills
genus Epilachna: genus of ladybugs native to Mexico and Central America; both larvae and adults feed on plants
genus Epinephelus: genus of groupers or sea bass
genus Eptatretus: a genus of fossil fish of the family Myxinidae
genus Eptesicus: a genus of Vespertilionidae
genus Equetus: drumfish
genus Equus: type genus of the Equidae: only surviving genus of the family Equidae
genus Erethizon: a genus of Erethizontidae
genus Eretmochelys: hawksbills
genus Erignathus: bearded seals
genus Erinaceus: type genus of the family Erinaceidae: hedgehogs
genus Eriosoma: woolly aphids
genus Erithacus: Old World thrushes
genus Erolia: a genus of Scolopacidae
genus Erwinia: a genus of bacteria
genus Erythrocebus: patas
genus Escherichia: a genus of bacteria
genus Eschrichtius: type and sole genus of the Eschrichtiidae
genus Esox: type and only genus of the family Esocidae
genus Estrilda: avadavats
genus Etropus: a genus of Bothidae
genus Euarctos: American black bears; in some classifications not a separate genus from Ursus
genus Eucinostomus: a genus of Gerreidae
genus Euderma: a genus of Vespertilionidae
genus Eudyptes: rock hoppers
genus Euglena: type genus of the family Euglenaceae: green algae with a single flagellum
genus Eumeces: New World skinks
genus Eumenes: mason wasps
genus Eumetopias: sea lions
genus Eumops: mastiff bats
genus Eunectes: anacondas
genus Euphagus: a genus of Icteridae
genus Euphractus: a genus of Dasypodidae
genus Euplectella: a genus of Hyalospongiae
genus Euproctis: a genus of Lymantriidae
genus Euryale: basket stars
genus Eutamias: chipmunks of western America and Asia
genus Euthynnus: a genus of Scombridae
genus Exaeretodon: a genus of reptiles of the division Cynodontia
genus Falco: a genus of Falconidae
genus Fasciola: a genus of Fasciolidae
genus Fasciolopsis: a genus of Fasciolidae
genus Felis: type genus of the Felidae: true cats and most wildcats
genus Fissurella: type genus of the family Fissurellidae: keyhole limpets
genus Fistularia: type genus of the family Fistulariidae
genus Forficula: type genus of Forficulidae
genus Formica: type genus of the Formicidae
genus Formicarius: type genus of the Formicariidae
genus Fossa: monotypic genus of Madagascar civets closely related to palm civets
genus Francisella: a genus of Gram-negative aerobic bacteria that occur as pathogens and parasite in many animals (including humans)
genus Frankliniella: tobacco thrips
genus Fratercula: puffins
genus Fregata: type genus of the Fregatidae
genus Fringilla: type genus of the Fringillidae: chaffinch, brambling
genus Fucus: type genus of the family Fucaceae: cartilaginous brown algae
genus Fulica: coots
genus Fulmarus: fulmars
genus Fundulus: killifish
genus Fungia: a genus comprising the usual mushroom corals
genus Furnarius: type genus of the family Furnariidae: ovenbirds
genus Gadus: type genus of the Gadidae: the typical codfishes
genus Galago: bush babies
genus Galeocerdo: tiger sharks
genus Galeorhinus: a genus of Carcharhinidae
genus Galictis: alternative name for the genus Grison
genus Galleria: a genus of Pyralidae
genus Gallinago: snipes
genus Gallinula: gallinules
genus Gallirallus: rails of New Zealand
genus Gallus: common domestic birds and related forms
genus Gambelia: leopard lizards
genus Gambusia: mosquitofish
genus Garrulus: type genus of the Garrulinae: Old World jays
genus Gasterophilus: type genus of the Gasterophilidae: horse botflies
genus Gastrophryne: primarily tropical narrow-mouthed toads
genus Gavia: type genus of the Gavidae: loons
genus Gavialis: type genus of the Gavialidae
genus Gazella: typical gazelles
genus Gelechia: type genus of the Gelechiidae: pink bollworms
genus Gempylus: type genus of the Gempylidae
genus Genetta: genets
genus Genyonemus: a genus of Sciaenidae
genus Geochelone: giant tortoises
genus Geococcyx: roadrunners
genus Geomys: type genus of the Geomyidae
genus Geophilus: type genus of the Geophilidae: a cosmopolitan genus of centipedes sometimes called earwigs
genus Geothlypis: yellowthroats
genus Gerbillus: type genus of the Gerbillinae: typical gerbils
genus Gerres: type genus of the Gerreidae
genus Gerrhonotus: alligator lizards
genus Gerris: type genus of the Gerrididae
genus Giardia: flagellates parasitic in intestines of vertebrates
genus Ginglymostoma: nurse sharks
genus Giraffa: type genus of the Giraffidae
genus Glareola: type genus of the Glareolidae: the pratincoles
genus Glaucomys: New World flying squirrels
genus Glis: type genus of the Gliridae
genus Globicephala: pilot whales
genus Globigerina: type genus of the family Globigerinidae
genus Glossina: type genus of the Glossinidae: tsetse flies
genus Glossopsitta: a genus of Loriinae
genus Gobiesox: type genus of the Gobiesocidae
genus Gobio: true gudgeons
genus Gomphotherium: type genus of the Gomphotheriidae
genus Gonorhynchus: slender cylindrical marine fishes lacking air bladders and teeth
genus Gopherus: gopher tortoises
genus Gorgonocephalus: basket stars
genus Gorilla: gorillas
genus Gracula: mynas
genus Grampus: grampus
genus Grison: a genus of Mustelidae
genus Grus: type genus of the Gruidae: typical cranes
genus Gulo: a genus of Mustelidae
genus Gymnelis: a genus of Zoarcidae
genus Gymnogyps: containing solely the California condor
genus Gymnorhina: in some classifications placed in the family Laniidae: Australian piping crows
genus Gymnura: butterfly rays
genus Gypaetus: in some classifications the type genus of the family Aegypiidae
genus Gyps: a genus of Accipitridae
genus Haematobia: European genus of bloodsucking flies
genus Haematopus: oystercatchers
genus Haemopis: leeches
genus Haemoproteus: type genus of the family Haemoproteidae
genus Haemulon: type genus of the Haemulidae
genus Halcyon: a large kingfisher widely distributed in warmer parts of the Old World
genus Haldea: ground snakes
genus Haliaeetus: a genus of Accipitridae
genus Halicoeres: a genus of Labridae
genus Haliotis: type genus of the family Haliotidae
genus Haminoea: common genus of marine bubble shells of the Pacific coast of North America
genus Harpia: a genus of Accipitridae
genus Heliobacter: a genus of helical or curved or straight aerobic bacteria with rounded ends and multiple flagella; found in the gastric mucosa of primates (including humans)
genus Heliothis: a genus of Noctuidae
genus Helix: type genus of the family Helicidae
genus Heloderma: type genus of the Helodermatidae; American venomous lizards
genus Hemachatus: ringhals
genus Hemigalus: banded palm civets
genus Hemigrammus: tetras
genus Hemipteronatus: razor fish
genus Hemitripterus: sea ravens
genus Hermissenda: genus of marine sea slugs
genus Herpestes: mongooses
genus Herrerasaurus: primitive theropod found in Argentina; early Triassic
genus Hesperiphona: evening grosbeak
genus Heterocephalus: sand rats
genus Heterodon: a genus of small colubrid snakes containing the North American hognose snakes
genus Heteroscelus: tattlers
genus Hexagrammos: type genus of the Hexagrammidae
genus Hexamita: flagellates free-living or parasitic in intestines of birds
genus Hexanchus: a genus of Hexanchidae
genus Himantopus: major one of two genera of stilts; similar to avocets but with straight bills
genus Hippobosca: type genus of the Hippoboscidae
genus Hippocampus: seahorses
genus Hippodamia: genus of ladybugs
genus Hippoglossoides: a genus of Pleuronectidae
genus Hippoglossus: halibuts
genus Hippopotamus: type genus of the Hippopotamidae
genus Hipposideros: horseshoe bats
genus Hippotragus: sable antelopes
genus Hipsurus: a genus of Embiotocidae
genus Hirudo: type genus of the family Hirudinidae
genus Hirundo: type genus of the Hirundinidae
genus Holbrookia: earless lizards
genus Holocentrus: type genus of the family Holocentridae; squirrelfishes
genus Holothuria: type genus of the Holothuridae
genus Homarus: type genus of the family Homaridae: common edible lobsters
genus Homo: type genus of the family Hominidae
genus Homona: tea tortrix
genus Hyaena: type genus of the Hyaenidae
genus Hyalophora: American silkworm moth
genus Hydra: hydras
genus Hydrobates: type genus of the Hydrobatidae
genus Hydrochoerus: a genus of Hydrochoeridae
genus Hydrodamalis: a genus of the family Dugongidae comprising only Steller's sea cow
genus Hydromantes: web-toed salamanders
genus Hydromys: water rats
genus Hyemoschus: water chevrotains
genus Hyla: the type genus of the Hylidae; tree toads
genus Hylactophryne: barking frogs
genus Hylobates: gibbons
genus Hylocichla: American thrush: wood thrush; hermit thrush; veery
genus Hylophylax: a genus of Formicariidae
genus Hynerpeton: earliest fossil amphibian ever found; of the Devonian; found in Pennsylvania
genus Hypentelium: a genus of fish in the family Catostomidae
genus Hyperoglyphe: a genus of Stromateidae
genus Hyperoodon: bottle-nosed whales
genus Hyphantria: fall webworms
genus Hypoderma: in some classifications considered the type genus of the family Hypodermatidae: warble flies
genus Hypopachus: sheep frogs
genus Hypsiglena: night snakes
genus Hypsiprymnodon: musk kangaroos
genus Hyracotherium: extinct horse genus; formerly called eohippus
genus Ibero-mesornis: a genus of fossil bird of the subclass Archaeornithes
genus Ibis: ibises
genus Ichthyosaurus: type genus of the Ichthyosauridae
genus Ichthyostega: second earliest fossil amphibian ever found; of the Devonian; found in Greenland
genus Ictalurus: channel catfishes
genus Icteria: New World chats
genus Icterus: type genus of the Icteridae
genus Ictiobus: buffalo fishes
genus Ictonyx: a genus of Mustelidae
genus Iguana: type genus of the Iguanidae
genus Iguanodon: type genus of the Iguanodontidae
genus Inachis: a genus of Nymphalidae
genus Indri: type genus of the Indriidae
genus Irena: type genus of the Irenidae: fairy bluebirds
genus Iridoprocne: a genus of Hirundinidae
genus Ischigualastia: early reptile found in Argentina
genus Istiophorus: type genus of the Istiophoridae
genus Isurus: mako sharks
genus Ixobrychus: bitterns
genus Ixodes: type genus of the family Ixodidae
genus Jabiru: jabirus
genus Jaculus: jerboas
genus Javanthropus: former genus of primitive man; now Homo soloensis: comprises Solo man
genus Jordanella: flagfishes
genus Junco: American finches
genus Jynx: wrynecks
genus Kalotermes: type genus of Kalotermitidae; termites destructive of wood and living trees
genus Katsuwonus: oceanic bonitos; in some classifications placed in its own family Katsuwonidae
genus Kenyapithecus: extinct primate having powerful chewing muscles along with large molars and small incisors; fossils found in Kenya
genus Kinosternon: type genus of the Kinosternidae
genus Klebsiella: a genus of bacteria
genus Kobus: African antelopes: waterbucks
genus Kogia: pygmy sperm whales
genus Krypterophaneron: a genus of fish in the family Anomalopidae
genus Kyphosus: type genus of the Kyphosidae
genus Lacerta: type genus of the Lacertidae
genus Lachnolaimus: a genus of Labridae
genus Lactobacillus: type genus of the family Lactobacillaceae
genus Lactophrys: a genus of Ostraciidae
genus Lagidium: a genus of Chinchillidae
genus Lagodon: a genus of Sparidae
genus Lagopus: ptarmigans
genus Lagorchestes: hare wallabies
genus Lagostomus: viscachas
genus Lagothrix: woolly monkeys
genus Lama: llamas
genus Lambis: scorpion shells of shallow tropical waters of the eastern hemisphere
genus Laminaria: type genus of the family Laminariaceae: perennial brown kelps
genus Lamna: a genus of Lamnidae
genus Lampris: type genus of the Lampridae
genus Lampropeltis: king snakes and milk snakes
genus Lanius: type genus of the Laniidae: typical shrikes
genus Lanthanotus: one species
genus Larus: type genus of the Laridae
genus Lasiocampa: type genus of the Lasiocampidae: eggars
genus Lasiurus: a genus of Vespertilionidae
genus Lates: a genus of large percoid fishes of fresh and brackish water
genus Latimeria: type genus of the Latimeridae: coelacanth
genus Latrodectus: venomous spiders
genus Lebistes: guppies
genus Leiopelma: type and sole genus of the family Leiopelmatidae
genus Leipoa: mallee fowl
genus Leishmania: flagellate protozoan that causes leishmaniasis
genus Lemur: type genus of the Lemuridae
genus Leontocebus: tamarins
genus Lepas: type genus of the family Lepadidae
genus Lepidochelys: ridleys
genus Lepidocybium: a genus of Gempylidae
genus Lepisma: type genus of the Lepismatidae: silverfish
genus Lepisosteus: type genus of the Lepisosteidae: freshwater gars
genus Lepomis: bream
genus Leptinotarsa: Colorado potato beetles
genus Leptodactylus: type genus of the Leptodactylidae; in some classifications placed in the family Bufonidae
genus Leptoglossus: leaf-footed bugs
genus Leptoptilus: adjutant birds and marabous
genus Leptospira: very slender aerobic spirochetes; free-living or parasitic in mammals
genus Leptotyphlops: blind snakes of Asia and Africa and Americas
genus Lepus: type genus of the Leporidae: hares
genus Leuciscus: a genus of fish including: dace, chub
genus Leucocytozoon: a genus of protoctist
genus Lichanura: boas of western North America
genus Limanda: a genus of Pleuronectidae; righteye flounders having a humped nose and small scales; the underside is often brightly colored
genus Limax: a genus of Limacidae
genus Limenitis: mainly dark northern butterflies with white wing bars
genus Limnocryptes: snipe
genus Limnodromus: dowitchers
genus Limosa: godwits
genus Limulus: type genus of the family Limulidae
genus Liomys: pocket mice
genus Liparis: type genus of the Liparididae: snailfishes
genus Liposcelis: a genus of Psocidae
genus Listeria: a genus of aerobic motile bacteria of the family Corynebacteriaceae containing small Gram-positive rods
genus Litocranius: antelopes of eastern Africa: gerenuks
genus Littorina: type genus of the family Littorinidae: periwinkles
genus Lobipes: a genus of Phalaropidae
genus Lobotes: type genus of the Lobotidae
genus Locusta: a genus of Acrididae
genus Lofortyx: California quail
genus Loligo: squids
genus Lophius: type genus of family Lophiidae
genus Lophodytes: a genus of Merginae
genus Lopholatilus: large brightly colored food fish of deep Atlantic waters
genus Lophophorus: monals
genus Loris: type genus of the Lorisidae
genus Lota: burbot
genus Loxia: crossbill
genus Loxodonta: a genus of Elephantidae
genus Loxostege: garden webworms
genus Lucilia: greenbottle flies
genus Lufengpithecus: a genus of Hominidae
genus Lumpenus: a genus of Stichaeidae
genus Lunda: puffins
genus Luscinia: nightingales
genus Lutjanus: type genus of the Lutjanidae: snappers
genus Lutra: in some classifications considered a genus of the subfamily Lutrinae
genus Luvarus: type genus of the Luvaridae
genus Lycaena: type genus of the Lycaenidae; small slender butterflies with upper surface of wings usually metallic blue or green or copper
genus Lycaeon: African hunting dog
genus Lycosa: type genus of the family Lycosidae
genus Lygus: plant-sucking bugs
genus Lymantria: type genus of the Lymantriidae; a pest (Lymantria means `destroyer')
genus Lynx: lynxes
genus Lyrurus: black grouse
genus Macaca: macaques; rhesus monkeys
genus Macrocephalon: maleos
genus Macrocheira: giant crabs of Japan
genus Macroclemys: includes the alligator snapping turtle
genus Macrodactylus: a genus of Melolonthidae
genus Macronectes: giant petrels
genus Macropus: type genus of the family Macropodidae: typical kangaroos and wallabies
genus Macrotis: a genus of Peramelidae
genus Macrotus: leafnose bats
genus Macrozoarces: a genus of Zoarcidae
genus Madoqua: genus comprising some small antelopes of eastern and northeastern Africa
genus Maeandra: brain corals
genus Magicicada: seventeen-year locust
genus Maja: type genus of the Majidae; nearly cosmopolitan in distribution
genus Makaira: marlins
genus Malaclemys: American terrapins
genus Malacosoma: tent caterpillars
genus Mallotus: capelins
genus Malopterurus: electric catfish
genus Mammuthus: extinct genus: mammoths
genus Mandrillus: baboons
genus Manduca: moths whose larvae are tobacco hornworms or tomato hornworms
genus Manis: type genus of the Manidae
genus Manta: a genus of Mobulidae
genus Mantis: type genus of the Mantidae: mantises
genus Marmota: marmots
genus Martes: martens
genus Masticophis: whip snakes
genus Mastigoproctus: giant whip scorpions
genus Mastodon: extinct type genus of the Mammutidae: mastodons
genus Mastotermes: primitive genus of termites; mostly extinct; sometimes considered the most primitive Isoptera
genus Maxostoma: a genus of fish in the family Catostomidae
genus Mayetiola: a genus of Cecidomyidae
genus Mazama: brockets
genus Megachile: type genus of the Megachilidae: leaf-cutting bees
genus Megaderma: type genus of the Megadermatidae
genus Megalobatrachus: giant salamanders; in some classifications included in the genus Cryptobranchus
genus Megalosaurus: type genus of the Megalosauridae
genus Megaptera: humpback whales
genus Megatherium: type genus of the Megatheriidae
genus Melanerpes: a genus of Picidae
genus Melanitta: scoters
genus Melanogrammus: haddock
genus Melanoplus: New World migratory locusts and common American grasshoppers
genus Melanotis: a genus of Mimidae
genus Meleagris: type genus of the Meleagrididae: wild and domestic turkeys
genus Meles: in some classifications: type genus of the subfamily Melinae
genus Mellivora: ratels
genus Melogale: a genus of Mustelidae
genus Melolontha: a genus of Melolonthidae
genus Melophagus: an arthropod genus of wingless flies including the sheep ked
genus Melopsittacus: a genus of Psittacidae
genus Melospiza: American song sparrow and swamp sparrow
genus Melursus: sloth bears; in some classifications not a separate genus from Ursus
genus Menippe: stone crabs
genus Menopon: chicken lice
genus Menticirrhus: kingfishes; whiting
genus Menura: type and sole genus of the family Menuridae
genus Mephitis: in some classifications: type genus of the subfamily Mephitinae
genus Mercenaria: a genus of Veneridae
genus Mergus: mergansers
genus Meriones: a genus of Cricetidae
genus Merlangus: whitings
genus Merluccius: hakes
genus Merops: type genus of the Meropidae
genus Mesocricetus: golden hamsters
genus Mesohippus: a genus of Equidae
genus Microcentrum: katydids
genus Micrococcus: type genus of the family Micrococcaceae
genus Microdipodops: kangaroo mice
genus Micromyx: Old World harvest mice
genus Micropogonias: croakers
genus Micropterus: American freshwater black basses
genus Microstomus: a genus of Pleuronectidae
genus Microtus: voles of the northern hemisphere
genus Micruroides: coral snakes
genus Micrurus: coral snakes
genus Mimus: type genus of the family Mimidae: mockingbirds
genus Mirounga: elephant seals
genus Mobula: type genus of the Mobulidae
genus Mola: type genus of the Molidae
genus Mollienesia: mollies
genus Moloch: genus of Australian desert lizard
genus Molothrus: cowbirds
genus Molva: ling
genus Momotus: type genus of the Momotidae
genus Monocanthus: type genus of the Monocanthidae
genus Monochamus: sawyer beetles
genus Monodon: type genus of the Monodontidae
genus Monomorium: a genus of Formicidae
genus Mononychus: authorities disagree over whether to classify the genus as bird or dinosaur
genus Morone: carnivorous fresh and salt water fishes
genus Moschus: musk deer
genus Motacilla: type genus of the Motacillidae: wagtails
genus Mugil: type genus of the Mugilidae: mullets
genus Mulloidichthys: a genus of Mullidae
genus Mullus: type genus of the Mullidae: goatfishes
genus Muntiacus: muntjacs
genus Mus: type genus of the Muridae: common house mice; the tips of the upper incisors have a square notch
genus Musca: type genus of the Muscidae: houseflies
genus Muscardinus: a genus of Gliridae
genus Muscicapa: type genus of the Muscicapidae
genus Muscivora: a genus of Tyrannidae
genus Musophaga: type genus of the Musophagidae
genus Mustela: type genus of the family Mustelidae: minks and weasels
genus Mustelus: smooth dogfishes
genus Mya: type genus of the family Myacidae
genus Myadestes: solitaires
genus Mycobacterium: nonmotile Gram-positive aerobic bacteria
genus Mycoplasma: type and sole genus of the family Mycoplasmataceae
genus Mycteria: a genus of storks of the family Ciconiidae now including only the American wood ibis
genus Mycteroperca: groupers
genus Mylodon: type genus of the Mylodontidae; sometimes included in family Megatheriidae
genus Myocastor: a genus of Capromyidae
genus Myopus: a genus of Cricetidae
genus Myotis: largest and most widely distributed genus of bats
genus Myrmecia: bulldog ants
genus Myrmecobius: banded anteater
genus Myrmecophaga: type genus of the Myrmecophagidae; South American ant bear
genus Myrmeleon: type genus of the Myrmeleontidae: antlions
genus Mysis: type genus of the family Mysidae
genus Mytilus: type genus of the family Mytilidae: smooth-shelled marine mussels
genus Myxine: type genus of the Myxinidae (typical hagfishes)
genus Myxinikela: fossil hagfishes
genus Myxocephalus: grubby
genus Naemorhedus: gorals
genus Naja: cobras
genus Nanomia: a genus of Siphonophora
genus Nasalis: proboscis monkeys
genus Nasua: coatis
genus Natrix: water snakes; a cosmopolitan genus
genus Naucrates: a genus of Carangidae
genus Nautilus: type genus and sole recent representative of the family Nautilidae
genus Necturus: a genus of Proteidae
genus Negaprion: lemon sharks
genus Neoceratodus: extant Australian lungfishes
genus Neofiber: round-tailed muskrat
genus Neomys: a genus of Soricidae
genus Neophron: a genus of Accipitridae
genus Neotoma: packrats
genus Nepa: type genus of the Nepidae: typical elongate-oval water scorpions
genus Nephrops: a genus of Nephropsidae
genus Nerita: type genus of the Neritidae
genus Neritina: a genus of Neritidae
genus Nerodia: North American water snakes
genus Nesokia: bandicoot rats
genus Nestor: a genus of Psittacidae
genus Neurotrichus: shrew moles
genus Nimravus: false sabertoothed tigers
genus Nitella: fragile branching stoneworts
genus Nitrobacter: rod-shaped soil bacteria
genus Nitrosomonas: ellipsoidal soil bacteria
genus Noctiluca: a genus of protoctist
genus Noctua: type genus of the Noctuidae: moths whose larvae are cutworms
genus Nomia: a genus of bee; some are important pollinators of legumes
genus Nostoc: type genus of the family Nostocaceae: freshwater blue-green algae
genus Notechis: tiger snakes
genus Notemigonus: golden shiners
genus Nothosaurus: a genus of Nothosauria
genus Notomys: jerboa rats
genus Notonecta: type genus of the Notonectidae: backswimmers
genus Notophthalmus: newts
genus Notornis: a genus of Rallidae
genus Notoryctus: type genus of the family Notoryctidae: comprising solely the marsupial mole
genus Notropis: shiners
genus Nucifraga: nutcrackers
genus Numenius: curlews
genus Numida: guinea fowl
genus Nyctanassa: American night herons
genus Nyctereutes: raccoon dogs
genus Nycticebus: a genus of Lorisidae
genus Nycticorax: Old World night herons
genus Nyctimene: East Indian fruit bats
genus Nymphalis: type genus of the Nymphalidae: mourning cloak butterflies
genus Nymphicus: a genus of Psittacidae
genus Oceanites: a genus of Hydrobatidae
genus Ochotona: type genus of the Ochotonidae
genus Octopus: type genus of the family Octopodidae
genus Ocyurus: snappers
genus Odobenus: type genus of the Odobenidae: walruses
genus Odocoileus: North American deer
genus Odontophorus: genus of Central and South American crested partridges resembling quails; sometimes placed in a distinct subfamily or isolated in a distinct family
genus Oecanthus: tree crickets
genus Oedogonium: type genus of Oedogoniaceae; freshwater green algae having long unbranched filaments; usually free-floating when mature
genus Oenanthe: wheatears
genus Oestrus: type genus of the Oestridae: sheep botflies
genus Okapia: okapis
genus Oligoplites: leatherjackets
genus Ommastrephes: a genus of Decapoda
genus Oncorhynchus: Pacific salmon including sockeye salmon; chinook salmon; chum salmon; coho salmon
genus Ondatra: muskrats
genus Oniscus: type genus of the Oniscidae; woodlice that cannot roll into a ball
genus Onychogalea: a genus of Macropodidae
genus Onychomys: grasshopper mice
genus Opheodrys: North American green snakes
genus Ophiodon: a genus of Ophiodontidae
genus Ophiophagus: king cobra
genus Ophisaurus: glass lizards
genus Opisthocomus: type genus of the Opisthocomidae: hoatzins
genus Orchestia: type genus of the family Orchestiidae
genus Orcinus: killer whales
genus Oreamnos: mountain goats
genus Orectolobus: carpet sharks
genus Oreortyx: mountain quail of western United States
genus Oriolus: type genus of the Oriolidae
genus Ornithorhynchus: type genus of the family Ornithorhynchidae
genus Ortalis: chachalacas
genus Orthopristis: a genus of Haemulidae
genus Orthotomus: tailorbirds
genus Orycteropus: coextensive with the family Orycteropodidae
genus Oryctolagus: Old World rabbits
genus Oryx: African antelopes: oryxes
genus Oryzomys: rice rats
genus Osmerus: type genus of the Osmeridae
genus Ostrea: type genus of the family Ostreidae
genus Otaria: type genus of the Otariidae
genus Otis: type genus of the Otididae: European bustard
genus Otus: a genus of Strigidae
genus Ouranopithecus: a genus of Hominidae
genus Ovalipes: a genus of Portunidae
genus Ovibos: consisting of the musk-ox
genus Ovis: sheep
genus Oxybelis: vine snakes
genus Oxylebius: a genus of Hexagrammidae
genus Oxyura: ruddy duck
genus Oxyuranus: taipans
genus Pachycephala: arboreal insectivorous birds
genus Padda: a genus of Ploceidae
genus Pagellus: sea breams
genus Pagophila: a genus of Laridae
genus Pagophilus: harp seals
genus Pagrus: a genus of Sparidae
genus Pagurus: type genus of the family Paguridae
genus Palaemon: type genus of the family Palaemonidae; widely distributed genus
genus Paleacrita: geometrid moths
genus Palinurus: type genus of the family Palinuridae
genus Palometa: a genus of Stromateidae
genus Pan: chimpanzees; more closely related to Australopithecus than to other pongids
genus Pandion: type genus of the Pandionidae
genus Panonychus: a genus of Tetranychidae
genus Panthera: lions; leopards; snow leopards; jaguars; tigers; cheetahs; saber-toothed tigers
genus Papio: baboons
genus Paprilus: a genus of Stromateidae
genus Paracheirodon: a genus of Characidae
genus Paradoxurus: palm civets
genus Paralichthys: a genus of Bothidae
genus Paralithodes: a genus of Lithodidae
genus Paramecium: freshwater ciliate with an oval body and long deep oral groove
genus Paranthias: a genus of Serranidae
genus Paranthropus: former classification for Australopithecus robustus
genus Parascalops: brewer's moles
genus Parophrys: a genus of Soleidae
genus Parula: type genus of the Parulidae: wood warblers
genus Parus: type genus of the family Paridae
genus Passer: type genus of the Passeridae
genus Passerina: a genus of small North American finches including the New World buntings
genus Patella: type genus of the family Patellidae: common European limpets
genus Pavo: peafowl
genus Pecten: type genus of the family Pectinidae: sea and bay scallops
genus Pediculus: type genus of Pediculidae: true lice infecting humans
genus Pedioecetes: sharp-tailed grouse
genus Pedionomus: plain wanderer
genus Pelecanus: type genus of the Pelecanidae
genus Penelope: a genus of guans (turkey-like arboreal birds valued as game and food birds)
genus Peneus: type genus of the family Peneidae
genus Pennatula: type genus of the family Pennatulidae: sea pens
genus Perca: type genus of the Percidae
genus Percina: a genus of Percidae
genus Perdix: a genus of Perdicinae
genus Peridinium: type genus of the family Peridiniidae
genus Periophthalmus: a genus of Gobiidae
genus Peripatopsis: type genus of Peripatopsidae; onychophorans of chiefly Asiatic and African tropical regions
genus Peripatus: type genus of Peripatidae; onychophorans of chiefly New World tropical regions
genus Periplaneta: cosmopolitan genus of large cockroaches
genus Perisoreus: Canada jays
genus Peristedion: in some classifications the type genus of the subfamily Peristediinae: armored sea robins
genus Pernis: a common European bird of prey; dull brown with white-streaked underparts
genus Perodicticus: a genus of Lorisidae
genus Perognathus: pocket mice
genus Peromyscus: New World wood mice
genus Petaurista: very large Asiatic flying squirrels
genus Petaurus: a genus of Phalangeridae
genus Petrogale: rock wallabies
genus Petromyzon: typical lampreys
genus Pezophaps: constituted by the extinct solitaire
genus Phacochoerus: warthogs
genus Phaethon: type genus of the Phaethontidae
genus Phalacrocorax: type genus: coextensive with the family Phalacrocoracidae
genus Phalaenoptilus: a genus of Caprimulgidae
genus Phalanger: type genus of the family Phalangeridae: cuscuses
genus Phalangium: type genus of the family Phalangiidae
genus Phalaropus: type genus of the Phalaropidae: phalaropes
genus Pharomacrus: a genus of Trogonidae
genus Phascogale: pouched mice
genus Phascolarctos: koalas
genus Phasianus: type genus of the Phasianidae: the typical pheasants
genus Phenacomys: North American voles
genus Philaenus: a genus of Cercopidae
genus Philohela: American woodcocks
genus Philomachus: ruffs
genus Philophylla: leaf miners
genus Phlebotomus: small bloodsucking sand flies that resemble moths
genus Phoca: type genus of the Phocidae: earless seals
genus Phocoena: porpoises
genus Phoeniculus: type and only genus of the family Phoeniculidae
genus Phoenicurus: Old World thrushes
genus Pholas: type genus of the family Pholadidae: piddocks
genus Pholis: type genus of the Pholidae: gunnels
genus Photoblepharon: a genus of fish in the family Anomalopidae
genus Phoxinus: minnows
genus Phrynosoma: horned lizards
genus Phthirius: true lice: crab lice
genus Phthorimaea: potato moths
genus Phyllium: type genus of the Phyllidae
genus Phyllorhynchus: leaf-nosed snakes
genus Phylloscopus: warblers
genus Phyllostomus: type genus of the family Phyllostomatidae
genus Phylloxera: type genus of the Phylloxeridae: plant lice
genus Physa: type genus of the Physidae; freshwater air-breathing snails
genus Physalia: Portuguese man-of-war
genus Physeter: type genus of the Physeteridae
genus Pica: magpies
genus Picoides: a genus of Picidae
genus Picumnus: a genus of Picidae
genus Picus: type genus of Picidae
genus Pieris: type genus of the Pieridae
genus Pinctada: pearl oysters
genus Pineus: a genus of Adelgidae
genus Pinguinus: great auk
genus Pinicola: a genus of Fringillidae
genus Pinnotheres: type genus of the family Pinnotheridae: pea crabs
genus Pipa: type genus of the Pipidae
genus Pipile: genus of large crested guans (the piping guans)
genus Pipilo: towhees
genus Pipistrellus: nearly cosmopolitan genus of very small bats
genus Pipra: type genus of the Pipridae containing the typical manakins
genus Piranga: a genus of Thraupidae
genus Piroplasma: type genus of the family Babesiidae
genus Pisanosaurus: primitive ornithischian dinosaur found in Argentina; early Triassic
genus Pithecia: sakis
genus Pitta: type genus of the Pittidae; a large genus of birds of southern Asia and Australia and adjacent islands
genus Pituophis: bull snakes
genus Pitymys: pine mice
genus Placuna: windowpane oysters
genus Planococcus: a genus of Pseudococcidae
genus Plasmodium: type genus of the family Plasmodiidae
genus Platalea: type genus of the Plataleidae
genus Platichthys: a genus of Pleuronectidae
genus Platypoecilus: platys
genus Plautus: a genus of Alcidae
genus Plecotus: a genus of Vespertilionidae
genus Plectrophenax: snow bunting
genus Plesianthropus: former name for the genus Australopithecus
genus Plesiosaurus: a reptile genus of suborder Plesiosauria
genus Plethodon: type genus of the Plethodontidae
genus Pleurobrachia: sea gooseberries
genus Pleuronectes: type genus of the Pleuronectidae
genus Plicatoperipatus: a genus of Peripatidae
genus Ploceus: type genus of the Ploceidae
genus Pluvialis: golden plovers
genus Pluvianus: coursers
genus Podargus: type genus of the Podargidae
genus Podiceps: type genus of the Podicipedidae: grebes
genus Podilymbus: a genus of Podicipedidae
genus Poecilocapsus: a genus of Miridae
genus Poecilogale: muishonds
genus Poephila: grassfinches
genus Polioptila: New World gnatcatchers
genus Polistes: a genus of Vespidae
genus Pollachius: pollack
genus Polyangium: type genus of the family Polyangiaceae: myxobacteria with rounded fruiting bodies enclosed in a membrane
genus Polyborus: a genus of Falconidae
genus Polycirrus: genus of soft-bodied polychete marine worms
genus Polydactylus: a genus of Polynemidae
genus Polyergus: Amazon ants
genus Polygonia: comma butterflies
genus Polyodon: type genus of the Polyodontidae
genus Polypedates: type genus of the Polypedatidae
genus Polyprion: wreckfish
genus Pomacanthus: angelfishes
genus Pomacentrus: type genus of the Pomacentridae: damselfishes
genus Pomatomus: type genus of the Pomatomidae
genus Pomolobus: genus to which the alewife is sometimes assigned
genus Pomoxis: crappies
genus Pongo: type genus of the family Pongidae: orangutans
genus Pooecetes: a genus of Fringillidae
genus Popillia: a genus of Scarabaeidae
genus Porcellio: Old World genus of isopod crustaceans
genus Poronotus: a genus of Stromateidae
genus Porphyra: a genus of protoctist
genus Porphyrio: Old World purple gallinules
genus Porphyrula: American purple gallinules
genus Portunus: type genus of the family Portunidae
genus Porzana: spotted crakes
genus Potamogale: type genus of the family Potamogalidae: otter shrews
genus Potamophis: ground snakes
genus Potorous: potoroos
genus Potos: a genus of Procyonidae
genus Praunus: a genus of Mysidae
genus Priacanthus: type genus of the Priacanthidae
genus Prinia: a genus of Sylviidae
genus Priodontes: solely the giant armadillo
genus Prionace: blue sharks
genus Prionotus: a genus of Triglidae
genus Pristis: type genus of the Pristidae
genus Procavia: type genus of the Procaviidae
genus Procellaria: type genus of the Procellariidae
genus Prociphilus: a genus of Aphididae
genus Procnias: bellbirds
genus Proconsul: genus of extinct primitive African primates of the Miocene epoch; sometimes considered a subgenus of Dryopithecus
genus Procyon: the type genus of the family Procyonidae: raccoons
genus Progne: a genus of Hirundinidae
genus Prosopium: whitefishes
genus Proteles: aardwolf
genus Proterochampsa: early archosaurian carnivore
genus Proteus: type genus of the Proteidae
genus Protoavis: extinct primitive birds of the Triassic period; 70 million years before archaeopteryx
genus Protoceratops: small horned dinosaurs
genus Protohippus: a genus of Equidae
genus Prunella: type genus of the Prunellidae
genus Psaltriparus: a genus of Paridae
genus Psenes: a genus of Stromateidae
genus Psephurus: a genus of Polyodontidae
genus Psetta: a genus of Bothidae
genus Psettichthys: a genus of Soleidae
genus Pseudacris: chorus frogs
genus Pseudaletia: moths whose larvae are armyworms
genus Pseudechis: venomous Australian blacksnakes
genus Pseudemys: sliders; red-bellied terrapin
genus Pseudococcus: type genus of the Pseudococcidae
genus Pseudomonas: type genus of the family Pseudomonodaceae
genus Pseudopleuronectes: a genus of Pleuronectidae
genus Pseudoryx: species of large cow-like mammals of Vietnam discovered by scientists in 1992
genus Psithyrus: a large bee that resembles the bumblebee but lacks pollen-collecting apparatus and a worker caste
genus Psittacosaurus: most primitive genus of horned dinosaurs; early Cretaceous
genus Psittacula: a genus of Psittacidae
genus Psittacus: type genus of the Psittacidae: usually restricted to the African grey
genus Psophia: type genus of the Psophiidae: trumpeters
genus Pternohyla: burrowing tree frogs
genus Pterocles: type genus of the Pteroclididae
genus Pterocnemia: a genus of birds of the family Rheidae
genus Pterodactylus: a reptile genus of Pterodactylidae
genus Pterois: lionfishes
genus Pteropus: a genus of Megachiroptera
genus Ptilocercus: pentails
genus Ptilocrinus: sea lilies
genus Ptilonorhynchus: type genus of the Ptilonorhynchidae
genus Ptloris: a genus of Paradisaeidae
genus Ptyas: Asian rat snakes
genus Ptychozoon: flying geckos
genus Puffinus: shearwaters
genus Pulex: type genus of the Pulicidae
genus Pygopus: type genus of the Pygopodidae; snake-shaped pleurodont lizard with no forelimbs and only rudimentary hind limbs
genus Pygoscelis: a genus of Spheniscidae
genus Pylodictus: flathead catfishes
genus Pyralis: type genus of the Pyralidae
genus Pyrausta: moths whose larvae are corn borers
genus Pyrocephalus: a genus of Tyrannidae
genus Pyrophorus: tropical click beetles
genus Pyrrhula: bullfinches
genus Pyrrhuloxia: large showy finches related to cardinals
genus Python: Old World boas
genus Quiscalus: grackles
genus Rachycentron: genus and family are coextensive and comprise only the cobia
genus Raja: type genus of the family Rajidae
genus Ramphomicron: thornbills
genus Rana: type genus of the Ranidae
genus Ranatra: elongate very slender water scorpions
genus Rangifer: reindeer or caribou
genus Raphicerus: African antelopes: steenboks
genus Raphus: type genus of the Raphidae: dodos
genus Rattus: common house rats; upper incisors have a beveled edge
genus Recurvirostra: type genus of the Recurvirostridae: avocets
genus Regalecus: type genus of the Regalecidae
genus Regulus: a genus of birds of the family Sylviidae including kinglets
genus Reithrodontomys: New World harvest mice
genus Remilegia: a genus of Echeneididae
genus Reticulitermes: includes species highly destructive to structures and living trees
genus Rhagoletis: a genus of Trypetidae
genus Rhea: type genus of the Rheidae; large tall flightless South American birds similar to but smaller than ostriches
genus Rhincodon: whale sharks
genus Rhinoceros: type genus of the Rhinocerotidae
genus Rhinonicteris: orange horseshoe bats
genus Rhinoptera: a genus of Myliobatidae
genus Rhizobium: the type genus of Rhizobiaceae; usually occur in the root nodules of legumes; can fix atmospheric oxygen
genus Rhodymenia: type genus of the family Rhodymeniaceae
genus Rhyacotriton: olympic salamanders
genus Rhynchoelaps: Australian coral snakes
genus Richmondena: cardinals
genus Rickettsia: can cause typhus and Rocky Mountain spotted fever in humans
genus Riparia: a genus of Hirundinidae
genus Rissa: a genus of Laridae
genus Rivulus: killifish
genus Roccus: a genus of Serranidae
genus Rupicapra: chamois
genus Rupicola: cock of the rocks
genus Rutilus: roaches
genus Rynchops: type genus of the Rynchopidae: skimmers
genus Rypticus: a genus of fish of the family Serranidae, including soapfishes
genus Sagitta: chief genus of Chaetognatha including the largest arrowworms
genus Sagittarius: type genus of the Sagittariidae
genus Saiga: Eurasian antelopes: saigas
genus Saimiri: squirrel monkeys
genus Salamandra: type genus of the Salamandridae
genus Salmo: type genus of the Salmonidae: salmon and trout
genus Salmonella: a genus of bacteria
genus Salpa: type (perhaps sole) genus of the Salpidae
genus Salpinctes: a genus of Troglodytidae
genus Salvelinus: brook trout
genus Samia: silkworm moths
genus Sarcocystis: chief genus of the order Sarcosporidia
genus Sarcophaga: flesh flies
genus Sarcophilus: Tasmanian devil
genus Sarcoptes: type genus of the family Sarcoptidae: itch mites
genus Sarcorhamphus: usually containing only the king vulture
genus Sarda: bonitos
genus Sardinia: pilchards
genus Sardinops: pilchards
genus Sargassum: a genus of protoctist
genus Saturnia: type genus of the Saturniidae: emperor moth
genus Sauromalus: chuckwallas
genus Saurosuchus: early archosaurian carnivore
genus Saxicola: Old World chats
genus Sayornis: phoebes
genus Scaphiopus: New World spadefoot toads
genus Scarabaeus: type genus of the Scarabaeidae
genus Scardinius: rudds
genus Scartella: a genus of Blenniidae
genus Sceliphron: mud daubers
genus Sceloglaux: a genus of Strigidae
genus Sceloporus: spiny lizards
genus Schistosoma: type genus of the family Schistosomatidae: blood flukes
genus Sciaena: type genus of the Sciaenidae: croakers
genus Sciaenops: a genus of Sciaenidae
genus Sciara: type genus of the Sciaridae: fungus gnat
genus Scincella: a reptile genus of Scincidae
genus Scincus: type genus of Scincidae
genus Sciurus: type genus of the Sciuridae; typical moderate-sized arboreal squirrels
genus Scleropages: a genus of large freshwater fishes of Australia and Borneo
genus Scolopax: type of the Scolopacidae: Old World woodcocks
genus Scolytus: type genus of the Scolytidae comprising numerous small bark beetles
genus Scomber: type genus of the Scombridae
genus Scomberesox: a genus of Scomberesocidae
genus Scomberomorus: Spanish mackerels
genus Scophthalmus: a genus of Bothidae
genus Scorpaena: type genus of the Scorpaenidae: scorpionfishes
genus Scutigera: a genus of Scutigeridae
genus Scutigerella: garden centipedes
genus Sebastodes: rockfishes
genus Seismosaurus: genus of large herbivorous dinosaurs of Cretaceous found in western North America
genus Seiurus: ovenbirds and water thrushes
genus Selar: big-eyed scad
genus Selenarctos: Asiatic black bears; in some classifications not a separate genus from Ursus
genus Selene: a genus of Carangidae
genus Sepia: type genus of the Sepiidae
genus Serinus: Old World finches; e.g. canaries and serins
genus Seriola: a genus of Carangidae
genus Seriphus: a genus of Sciaenidae
genus Serranus: type genus of the Serranidae: mostly small Pacific sea basses
genus Serrasalmus: piranhas
genus Serratia: a genus of motile peritrichous bacteria that contain small Gram-negative rod
genus Sertularia: sessile hydroid that forms feathery colonies
genus Setophaga: a genus of Parulidae
genus Shigella: a genus of bacteria
genus Sialia: North American bluebirds
genus Sialis: type genus of the Sialidae
genus Sigmodon: American cotton rats
genus Sillago: type genus of the Sillaginidae
genus Silurus: type genus of the Siluridae: catfishes
genus Silvia: type genus of the Sylviidae: warblers
genus Simulium: type genus of the Simuliidae: blackflies
genus Sinanthropus: genus to which Peking man was formerly assigned
genus Sinornis: a genus of fossil birds
genus Siren: a genus of Sirenidae
genus Sistrurus: pygmy rattlesnakes
genus Sitophylus: a genus of Bruchidae
genus Sitotroga: grain moths
genus Sitta: type genus of the Sittidae
genus Sivapithecus: extinct primates; lower Pliocene
genus Smiledon: saber-toothed tigers
genus Solea: type genus of the Soleidae
genus Solenopsis: fire ants
genus Somateria: eider ducks
genus Sonora: ground snakes
genus Sorex: type genus of the family Soricidae: shrews
genus Spadella: marine worms resembling the sagittas but with a broader body and only one pair of lateral fins
genus Spalax: type genus of the Spalacidae
genus Spermophilus: typical ground squirrels
genus Sphecius: large solitary wasps: cicada killer
genus Sphecotheres: a genus of Old World orioles
genus Spheniscus: type genus of the Spheniscidae: jackass penguins
genus Sphenodon: coextensive with the order Rhynchocephalia: tuataras
genus Sphyraena: type and sole genus of the Sphyraenidae: barracuda
genus Sphyrapicus: a genus of Picidae
genus Sphyrna: type genus of the Sphyrnidae
genus Spilogale: a genus of Mustelidae
genus Spinus: in some classifications considered a subgenus of Carduelis: siskins and New World goldfinches
genus Spirillum: a genus of bacteria
genus Spirochaeta: the type genus of the family Spirochaetaceae; a bacterium that is flexible, undulating, and chiefly aquatic
genus Spirogyra: a genus of protoctist
genus Spirula: genus of small cephalopods with many-chambered spiral shells resembling those of the extinct belemnites
genus Spizella: chipping sparrow; field sparrow; tree sparrow
genus Spodoptera: moths whose larvae are armyworms
genus Spyeria: fritillaries
genus Squalus: spiny dogfishes
genus Squatina: type genus of the Squatinidae: angel sharks
genus Squilla: type genus of the family Squillidae
genus Staphylococcus: includes many pathogenic species
genus Staurikosaurus: primitive ornithischian dinosaur found in Brazil
genus Steatornis: type and sole genus of the family Steatornithidae
genus Steganopus: a genus of Phalaropidae
genus Stegosaurus: quadrupedal armored herbivore of the Jurassic and Cretaceous
genus Stenopelmatus: sand crickets
genus Stenopterygius: a reptile genus of Ichthyosauridae
genus Stenotomus: scups
genus Stentor: trumpet-shaped protozoa with a ciliated spiral feeding funnel
genus Stercorarius: type genus of the Stercorariidae: jaegers
genus Sterna: a genus of Sterninae
genus Sternotherus: musk turtles
genus Stictomys: mountain pacas
genus Stictopelia: a genus of Columbidae
genus Stizostedion: pike-perches
genus Storeria: a genus of Colubridae
genus Strepera: bell magpies
genus Strepsiceros: African antelopes: kudus; bongos; nyalas; bushbucks
genus Streptococcus: a genus of bacteria
genus Streptomyces: type genus of the family Streptomycetaceae
genus Streptopelia: turtledoves
genus Strix: owls lacking ear tufts
genus Strombus: type genus of the family Strombidae
genus Struthio: type genus of the Struthionidae: African ostriches
genus Struthiomimus: small toothless saurischian dinosaurs; later Cretaceous period in Canada
genus Strymon: large and widely distributed genus of hairstreak butterflies
genus Sturnella: a genus of passerine birds including the meadowlarks
genus Sturnus: type genus of the Sturnidae: common starlings
genus Styracosaurus: genus of horned dinosaurs
genus Sula: type genus of the Sulidae
genus Suricata: meerkats
genus Surnia: a genus of hawk-like owls
genus Sus: type genus of the Suidae
genus Sylvilagus: North American rabbits
genus Symphalangus: used in some classifications for the siamangs
genus Synagrops: a genus of Serranidae
genus Synanceja: stonefishes
genus Synaptomys: bog lemmings
genus Synercus: Cape buffalo
genus Syngnathus: type genus of the family Syngnathidae
genus Syrrhaptes: a genus of Pteroclididae
genus Tachyglossus: type genus of the family Tachyglossidae
genus Tachypleus: a genus of Limulidae
genus Tadarida: freetail bats
genus Tadorna: sheldrakes
genus Taenia: type genus of the family Taeniidae: tapeworms
genus Tamandua: lesser anteater
genus Tamias: chipmunks of eastern North America
genus Tamiasciurus: American red squirrels
genus Tantilla: black-headed snakes
genus Tapirus: type genus of the Tapiridae
genus Taricha: Pacific newts
genus Tarpon: tarpons
genus Tarsius: type and sole genus of the family Tarsiidae
genus Taurotragus: African antelopes: elands
genus Tautoga: tautogs
genus Tautogolabrus: a genus of Labridae
genus Taxidea: in some classifications considered a genus of subfamily Melinae
genus Tayassu: type genus of the Tayassuidae
genus Tenrec: type genus of the family Tenrecidae: tenrecs
genus Terebella: type genus of Terebellidae; tube-forming marine polychete worms with many filamentous tentacles
genus Teredo: type genus of the family Teredinidae
genus Termes: type genus of the Termitidae
genus Terrapene: box turtles
genus Testudo: type genus of the Testudinidae
genus Tetragonurus: a genus of Stromateidae
genus Tetrahymena: protozoa having four membranous ciliary organelles
genus Tetrao: type genus of the Tetraonidae: capercaillies
genus Tetrapturus: a genus of Istiophoridae
genus Thalarctos: polar bears; in some classifications not a separate genus from Ursus
genus Thalassoma: a genus of Labridae
genus Thamnophilus: a genus of Formicariidae
genus Thamnophis: garter snakes
genus Thermobia: a genus of Lepismatidae
genus Thiobacillus: a genus of bacteria
genus Thomomys: western pocket gophers
genus Threskiornis: type genus of the Threskiornithidae
genus Thrips: type genus of the Thripidae
genus Thryothorus: Carolina wrens
genus Thunnus: tunas: warm-blooded fishes
genus Thylacinus: Tasmanian wolf
genus Thylogale: pademelons
genus Tibicen: harvest flies
genus Tichodroma: wall creepers; in some classifications placed in family Sittidae
genus Tilapia: a genus of Cichlidae
genus Timalia: type genus of the Timaliidae
genus Tinca: tench
genus Tinea: type genus of the Tineidae: clothes moths
genus Tineola: webbing clothes moths
genus Titanosaurus: genus of herbivorous dinosaurs flourishing during the Cretaceous in South America
genus Todus: type genus of the Todidae
genus Tolypeutes: a genus of Dasypodidae
genus Tomistoma: a genus of Malayan crocodiles
genus Tortrix: type genus of the Tortricidae
genus Toxostoma: thrashers
genus Toxotes: type genus of the Toxotidae
genus Trachinotus: a genus of Carangidae
genus Trachipterus: type genus of the Trachipteridae
genus Trachodon: a reptile genus of the suborder Euronithopoda
genus Trachurus: the scads (particularly horse mackerels)
genus Tragopan: a genus of Phasianidae
genus Tragulus: type genus of the Tragulidae
genus Treponema: type genus of Treponemataceae: anaerobic spirochetes with an undulating rigid body; parasitic in warm-blooded animals
genus Triaenodon: a genus of Triakidae
genus Trialeurodes: a genus of Aleyrodidae
genus Triatoma: conenoses
genus Tribolium: flour beetles
genus Tribonema: type genus of Tribonemaceae
genus Triceratops: genus of herbivorous horned dinosaurs
genus Trichecus: type and sole genus of the Trichechidae
genus Trichodesmium: a genus of blue-green algae
genus Trichoglossus: a genus of Loriinae
genus Trichomonas: flagellates parasitic in alimentary or genitourinary tracts of vertebrates and invertebrates including humans
genus Trichophaga: carpet moths
genus Trichosurus: a genus of Phalangeridae
genus Trichys: a genus of Hystricidae
genus Tridacna: type genus of the family Tridacnidae: giant clams
genus Triga: type genus of the Triglidae
genus Trimorphodon: lyre snakes
genus Trinectes: a genus of Soleidae
genus Tringa: a genus of Scolopacidae
genus Trionyx: type genus of the Trionychidae
genus Triops: type genus of the family Triopidae: small crustaceans with a small third median eye
genus Triturus: chiefly aquatic salamanders
genus Trogium: a genus of Psocidae
genus Troglodytes: type genus of the Troglodytidae
genus Trogon: type genus of the Trogonidae
genus Trombicula: type genus of the family Trombiculidae
genus Tropidoclonion: lined snakes
genus Tunga: a genus of Siphonaptera
genus Tupaia: the type genus of the Tupaia: chief genus of tree shrews
genus Tupinambis: tejus
genus Turdus: type genus of the Turdidae
genus Turnix: type genus of the Turnicidae: button quail
genus Tursiops: a genus of Delphinidae
genus Tylenchus: type genus of the family Tylenchidae
genus Tympanuchus: prairie chickens
genus Tyrannosaurus: includes a single species
genus Tyrannus: type genus of the Tyrannidae: tyrant flycatchers
genus Tyto: type and only genus of the family Tytonidae
genus Uca: fiddler crabs
genus Uintatherium: type genus of the Uintatheriidae; extinct large herbivorous ungulates somewhat resembling elephants; from the Eocene in Wyoming
genus Ulva: type genus of the family Ulvaceae; green seaweed having a thallus two cells thick: sea lettuce
genus Uma: fringe-toed lizard
genus Umbrina: croakers
genus Unio: type genus of the family Unionidae
genus Upupa: type genus of the Upupidae
genus Uria: murres
genus Urocyon: grey foxes
genus Urophycis: hakes
genus Uropsilus: shrew moles
genus Urosaurus: a reptile genus of Iguanidae
genus Ursus: type genus of Ursidae: brown bears; in some classifications genus Ursus includes all bears
genus Uta: a reptile genus of Iguanidae
genus Utahraptor: advanced bipedal carnivorous dinosaur
genus Vanellus: Eurasian lapwings
genus Vanessa: painted beauty and red admiral
genus Varanus: type and sole extant genus of the Varanidae
genus Vedalia: genus of Australian ladybugs
genus Velociraptor: advanced carnivorous theropod
genus Venus: type genus of the family Veneridae: genus of edible clams with thick oval shells
genus Vespa: type genus of the Vespidae: various hornets and yellow jackets
genus Vespertilio: a genus of Vespertilionidae
genus Vespula: sometimes considered a subgenus of Vespa: social wasps
genus Vibrio: a genus of bacteria
genus Vicugna: a genus of Camelidae
genus Vidua: whydahs
genus Vipera: type genus of the Viperidae
genus Vireo: type genus of the Vireonidae
genus Viverra: type genus of the family Viverridae
genus Viverricula: a genus of Viverridae
genus Volvox: type genus of the Volvocaceae; minute pale green flagellates occurring in tiny spherical colonies; minute flagella rotate the colony about an axis
genus Vorticella: ciliated protozoans that have a goblet-shaped body with a retractile stalk
genus Vulpes: foxes
genus Vultur: a bird that is usually restricted to the Andean condor
genus Xanthomonas: a genus of bacteria similar to Pseudomonas but producing a yellow pigment that is not soluble in water
genus Xenicus: type genus for the Xenicidae
genus Xenopus: an African clawed frog; in some classifications made the type genus of a separate family Xenopodidae
genus Xenorhyncus: East Indian and Australian storks
genus Xenosaurus: type and sole genus of Xenosauridae: slender-bodied Mexican lizards having the upper surface covered with tiny granules and tubercles
genus Xerobates: possible new genus for desert and Texas tortoises based on recent research
genus Xiphias: type genus of the Xiphiidae
genus Xylocopa: carpenter bees
genus Xyphophorus: swordtails
genus Zaglossus: a genus of Tachyglossidae
genus Zalophus: sea lions
genus Zapus: type genus of the Zapodidae
genus Zenaidura: mourning doves
genus Zeus: type genus of the family Zeidae
genus Zinjanthropus: genus to which Australopithecus boisei was formerly assigned
genus Zoarces: type genus of the Zoarcidae
genus Zonotrichia: large New World sparrows
genus Zygnema: type genus of the family Zygnemataceae
genus-Fenusa: birch leaf miner
genus-Megapodius: type genus of the Megapodiidae
genus-Milvus: a genus including the common European kits
Genyonemus lineatus: small silvery marine food fish found off California
Geococcyx californianus: speedy largely terrestrial bird found from California and Mexico to Texas
geoduck: a large edible clam found burrowing deeply in sandy mud along the Pacific coast of North America; weighs up to six pounds; has siphons that can extend to several feet and cannot be withdrawn into the shell
geometrid: slender-bodied broad-winged moth whose larvae are called measuring worms
Geomys bursarius: gopher of chiefly grasslands of central North America
Geomys pinetis: gopher of Alabama and Georgia and Florida
gerbil: small Old World burrowing desert rodent with long soft pale fur and hind legs adapted for leaping
germ layer: (embryology) any of the 3 layers of cells differentiated in embryos following gastrulation
German bee: dark-colored ill-tempered honeybee supposedly of German origin
German shepherd dog: breed of large shepherd dogs used in police work and as a guide for the blind
German short-haired pointer: liver or liver-and-white hunting dog developed in Germany; 3/4 pointer and 1/4 bloodhound
Gerres cinereus: popular panfish from Bermuda and Gulf of Mexico to Brazil
Gerris lacustris: a variety of water strider
giant: any creature of exceptional size
giant cockroach: large tropical American cockroaches
giant schnauzer: a large schnauzer
giant silkworm moth: any silkworm moth of the family Saturniidae
giant silkworm: larva of a saturniid moth; spins a large amount of strong silk in constructing its cocoon
giant tortoise: very large tortoises of the Galapagos and Seychelles islands
giant water bug: large water bug with piercing and sucking mouthparts; feeds on young fishes
giardia: a suspected cause of diarrhea in humans
gib: a castrated tomcat
Ginglymostoma cirratum: small bottom-dwelling shark of warm shallow waters on both coasts of North America and South America and from southeast Asia to Australia
Giraffa camelopardalis: tallest living quadruped; having a spotted coat and small horns and very long neck and legs; of savannahs of tropical Africa
glareole: Old World shorebird with long pointed wings and short legs; closely related to the coursers
glass lizard: snakelike lizard of Europe and Asia and North America with vestigial hind limbs and the ability to regenerate its long fragile tail
glass sponge: a siliceous sponge (with glassy spicules) of the class Hyalospongiae
Glaucomys sabrinus: large flying squirrel; chiefly of Canada
Glaucomys volans: small large-eyed nocturnal flying squirrel of eastern United States
gliding bacteria: bacteria that form colonies in self-produced slime; inhabit moist soils or decaying plant matter or animal waste
Glis glis: large European dormouse
Globicephala melaena: small dark-colored whale of the Atlantic coast of the United States; the largest male acts as pilot or leader for the school
globigerina: marine protozoan having a rounded shell with spiny processes
glossina: bloodsucking African fly; transmits sleeping sickness etc.
Glossopsitta versicolor: lorikeet with a colorful coat
glowworm: the luminous larva or wingless grub-like female of a firefly
gnat: (British usage) mosquito
gnat: any of various small biting flies: midges; biting midges; black flies; sand flies
gnatcatcher: very small North American and South American warblers
gnathostome: a vertebrate animal possessing true jaws
gnawer: relatively small placental mammals having a single pair of constantly growing incisor teeth specialized for gnawing
gnawing mammal: relative large gnawing animals; distinguished from rodents by having two pairs of upper incisors specialized for gnawing
gnu: large African antelope having a head with horns like an ox and a long tufted tail
goat antelope: bovid related to goats but having antelope-like features: mountain goats; gorals; serows; chamois; gnu goats
gobbler: male turkey
Gobiesox strumosus: clingfish with typical skillet shape
Gobio gobio: small slender European freshwater fish often used as bait by anglers
goby: small spiny-finned fish of coastal or brackish waters having a large head and elongated tapering body having the ventral fins modified as a sucker
godwit: large wading bird that resembles a curlew; has a long slightly upturned bill
golden algae: algae having the pigments chlorophyll and carotene and xanthophyll
golden mole: mole of southern Africa having iridescent guard hairs mixed with the underfur
golden plover: plovers of Europe and America having the backs marked with golden-yellow spots
golden retriever: an English breed having a long silky golden coat
goldeneye: a variety of green lacewing
gomphothere: extinct elephants of Central American and South America; of the Miocene and Pleistocene
Gonorhynchus gonorhynchus: fish of sandy areas of western Pacific and Indian oceans having an angular snout for burrowing into sand
goose: web-footed long-necked typically gregarious migratory aquatic birds usually larger and less aquatic than ducks
goose down: down of the goose
gopher: any of various terrestrial burrowing rodents of Old and New Worlds; often destroy crops
gopher: burrowing rodent of the family Geomyidae having large external cheek pouches; of Central America and southwestern North America
Gopherus agassizii: burrowing tortoise of the arid western United States and northern Mexico; may be reclassified as a member of genus Xerobates
Gopherus polypemus: burrowing edible land tortoise of southeastern North America
Gordon setter: a Scottish breed with a black-and-tan coat
gorgonian: corals having a horny or calcareous branching skeleton
Gorilla gorilla: largest anthropoid ape; terrestrial and vegetarian; of forests of central west Africa
Gorilla gorilla beringei: gorilla of Kivu highlands
Gorilla gorilla gorilla: a kind of gorilla
Gorilla gorilla grauri: a kind of gorilla
gosling: young goose
gracilariid: small dull or metallic-colored tineoid moths whose larvae mine in plant leaves
Gracula religiosa: glossy black Asiatic starling often taught to mimic speech
grade: a variety of cattle produced by crossbreeding with a superior breed
grain moth: moth whose larvae feed on grain
Grampus griseus: slaty-grey blunt-nosed dolphin common in northern seas
grass finch: usually brightly-colored Australian weaverbirds; often kept as cage birds
grass snake: either of two North American chiefly insectivorous snakes that are green in color
grasshopper mouse: insectivorous mouse of western North America
grasshopper: terrestrial plant-eating insect with hind legs adapted for leaping
gray hen: female black grouse
gray lemming: Old World lemming
gray mullet: freshwater or coastal food fishes a spindle-shaped body; found worldwide
gray: horse of a light gray or whitish color
great ape: any of the large anthropoid apes of the family Pongidae
Great Dane: very large powerful smooth-coated breed of dog
Great Pyrenees: bred of large heavy-coated white dogs resembling the Newfoundland
Greater Swiss Mountain dog: the largest of the four Swiss breeds
grebe: small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet
green gland: one of a pair of glands (believed to have excretory functions) in some crustaceans near the base of the large antennae
green June beetle: large greenish June beetle of southern United States
green mamba: green phase of the black mamba
green peach aphid: yellowish green aphid that is especially destructive to peaches
green plover: large crested Old World plover having wattles and spurs
green snake: any of numerous African colubrid snakes
greenbottle: blowfly with brilliant coppery green body
greeneye: bottom-dwellers having large eyes with metallic green luster
greenfly: greenish aphid; pest on garden and crop plants
greenling: food fish of the northern Pacific
gregarine: vermiform protozoans parasitic in insects and other invertebrates
grenadier: deep-sea fish with a large head and body and long tapering tail
greyhound: a tall slender dog of an ancient breed noted for swiftness and keen sight; used as a racing dog
griffon: breed of medium-sized long-headed dogs with downy undercoat and harsh wiry outer coat; originated in Holland but largely developed in France
groenendael: black-coated sheepdog with a heavily plumed tail
grosbeak: any of various finches of Europe or America having a massive and powerful bill
ground roller: Madagascan roller with terrestrial and crepuscular habits that feeds on e.g. insects and worms
ground sloth: gigantic extinct terrestrial sloth-like mammal of the Pliocene and Pleistocene in America
ground-shaker: huge herbivorous dinosaur of the Cretaceous found in western North America
grouper: usually solitary bottom sea basses of warm seas
grouse: popular game bird having a plump body and feathered legs and feet
grub: a soft thick wormlike larva of certain beetles and other insects
grunt: medium-sized tropical marine food fishes that utter grunting sounds when caught
Grus americana: rare North American crane having black-and-white plumage and a trumpeting call
guan: any of several large turkey-like game birds of the family Cracidae; native to jungles of tropical America; resembling the curassows and valued as food
guard dog: a dog trained to guard property
guard hair: coarse hairs that form the outer fur and protect the underfur of certain mammals
guenon: small slender African monkey having long hind limbs and tail and long hair around the face
Guernsey: breed of dairy cattle from the island of Guernsey
guide dog: a dog trained to guide the blind
guillemot: small black or brown speckled auks of northern seas
guinea hen: female guinea fowl
guitarfish: primitive tropical bottom-dwelling ray with a guitar-shaped body
gull: mostly white aquatic bird having long pointed wings and short legs
Gulo gulo: musteline mammal of northern Eurasia
Gulo luscus: stocky shaggy-coated North American carnivorous mammal
gun dog: a dog trained to work with sportsmen when they hunt with guns
gurnard: bottom-dwelling coastal fishes with spiny armored heads and fingerlike pectoral fins used for crawling along the sea bottom
Gymnelis viridis: brightly colored scaleless Arctic eelpout
Gymnogyps californianus: North American condor; chiefly dull black; almost extinct
Gymnorhina tibicen: crow-sized black-and-white bird; a good mimic often caged
Gypaetus barbatus: the largest Eurasian bird of prey; having black feathers hanging around the bill
Gyps fulvus: large vulture of southern Europe and northern Africa having pale plumage with black wings
hack: a saddle horse used for transportation rather than sport etc.
hack: a horse kept for hire
hack: an old or over-worked horse
hackle: long slender feather on the necks of e.g. turkeys and pheasants
hackney: a compact breed of harness horse
Haematobia irritans: small black European fly introduced into North America; sucks blood from cattle especially at the base of the horn
haemoproteid: related to malaria parasite and having a phase in the viscera of various birds
haemosporidian: minute protozoans parasitic at some stage of the life cycle in blood cells of vertebrates including many pathogens
Haemulon album: a grunt with a red mouth that is found from Florida to Brazil
Haemulon aurolineatum: found off the West Indies and Florida
Haemulon macrostomum: a kind of grunt
Haemulon malanurum: of warm Atlantic waters
Haemulon parra: a grunt found from Florida to Brazil and Gulf of Mexico
hag: eellike cyclostome having a tongue with horny teeth in a round mouth surrounded by eight tentacles; feeds on dead or trapped fishes by boring into their bodies
hair: a filamentous projection or process on an organism
hairstreak: small butterflies having striped markings under the wings
hake: any of several marine food fishes related to cod
halcyon: a mythical bird said to breed at the time of the winter solstice in a nest floating on the sea and to have the power of calming the winds and waves
halfbeak: tropical and subtropical marine and freshwater fishes having an elongated body and long protruding lower jaw
Haliaeetus leucocephalus: a large eagle of North America that has a white head and dark wings and body
Haliaeetus leucorhyphus: of southeast Europe and central Asia
Haliatus albicilla: bulky greyish-brown eagle with a short wedge-shaped white tail; of Europe and Greenland
halibut: marine food fish of the northern Atlantic or northern Pacific; the largest flatfish and one of the largest teleost fishes
Halicoeres bivittatus: small wrasse of tropical Atlantic
Halicoeres radiatus: bluish and bronze wrasse; found from Florida keys to Brazil
Haliotis tuberculata: an abalone found near the Channel Islands
halobacter: halophiles in saline environments such as the Dead Sea or salt flats
halophil: archaebacteria requiring a salt-rich environment for growth and survival
hammerhead: medium-sized live-bearing shark with eyes at either end of a flattened hammer-shaped head; worldwide in warm waters; can be dangerous
Hampshire down: British breed of hornless dark-faced domestic sheep
hamster: short-tailed Old World burrowing rodent with large cheek pouches
hand: terminal part of the forelimb in certain vertebrates (e.g. apes or kangaroos)
handsaw fish: a soft-finned fish of the genus Alepisaurus
hanging fly: any of various mecopterous insects of the family Bittacidae
haploid: (genetics) an organism or cell having only one complete set of chromosomes
haplosporidian: parasite in invertebrates and lower vertebrates of no known economic importance
hard tick: ticks having a hard shield on the back and mouth parts that project from the head
hard-shell crab: edible crab that has not recently molted and so has a hard shell
hare: swift timid long-eared mammal larger than a rabbit having a divided upper lip and long hind legs; young born furred and with open eyes
hare wallaby: small Australian wallaby that resembles a hare and has persistent teeth
harness horse: horse used for pulling vehicles
harnessed antelope: any of several antelopes of the genus Tragelaphus having striped markings resembling a harness
Harpia harpyja: large black-and-white crested eagle of tropical America
harpy: any of various fruit bats of the genus Nyctimene distinguished by nostrils drawn out into diverging tubes
harrier: a hound that resembles a foxhound but is smaller; used to hunt rabbits
harrier: hawks that hunt over meadows and marshes and prey on small terrestrial animals
harrier eagle: any of numerous large Old World hawks intermediate in some respects between typical hawks and typical eagles
hart: a male deer, especially an adult male red deer
hartebeest: a large African antelope with lyre-shaped horns that curve backward
hatchling: any recently hatched animal (especially birds)
haunch: the loin and leg of a quadruped
Hawaiian honeycreeper: small to medium-sized finches of the Hawaiian islands
hawk: diurnal bird of prey typically having short rounded wings and a long tail
hawk moth: any of various moths with long narrow forewings capable of powerful flight and hovering over flowers to feed
head: a single domestic animal
headfish: among the largest bony fish; pelagic fish having an oval compressed body with high dorsal and anal fins and caudal fin reduced to a rudder-like lobe; worldwide in warm waters
hearing dog: dog trained to assist the deaf by signaling the occurrence of certain sounds
heart urchin: sea urchin having a heart-shaped body in a rigid spiny shell
hedgehog: relatively large rodents with sharp erectile bristles mingled with the fur
heifer: young cow
Heliobacter pylori: the type species of genus Heliobacter; produces urease and is associated with several gastroduodenal diseases (including gastritis and gastric ulcers and duodenal ulcers and other peptic ulcers)
Heliothis zia: medium-sized moth whose larvae are corn earworms
Heliothis zia: larva of a noctuid moth; highly destructive to especially corn and cotton and tomato crops
heliozoan: protozoa with spherical bodies and stiff radiating pseudopods
Helix aspersa: serious garden pest having a brown shell with paler zigzag markings; nearly cosmopolitan in distribution
Helix hortensis: a kind of garden snail
Helix pomatia: one of the chief edible snails
helminth: worm that is parasitic on the intestines of vertebrates especially roundworms and tapeworms and flukes
Heloderma suspectum: large orange and black lizard of southwestern United States; not dangerous unless molested
Hemachatus haemachatus: highly venomous snake of southern Africa able to spit venom up to seven feet
Hemigalus hardwickii: an East Indian civet
Hemipteronatus novacula: a kind of razor fish
Hemitripterus americanus: large sculpin of western Atlantic; inflates itself when caught
hen: female of certain aquatic animals e.g. octopus or lobster
hen: adult female bird
hepadnavirus: a group of animal DNA viruses including viruses of ducks and woodchucks and squirrels and others as well as the virus causing hepatitis B in humans
hepatitis A virus: the virus causing hepatitis A
herbivore: any animal that feeds chiefly on grass and other plants
Hereford: hardy English breed of cattle raised extensively in United States
Hermissenda crassicornis: a kind of sea slug
hermit crab: small soft-bodied marine crustaceans living in cast-off shells of gastropods
heron: grey or white wading bird with long neck and long legs and (usually) long bill
herpes simplex: a herpes virus that affects the skin and nervous system
herpes varicella zoster: a herpes virus that causes chickenpox and shingles
herpes zoster: a herpes virus that causes shingles
herpes: any of the animal viruses that cause painful blisters on the skin
Herpestes ichneumon: northern African mongoose; in ancient times thought to devour crocodile eggs
herrerasaur: a kind of theropod dinosaur found in Argentina
Hesperiphona vespertina: North American grosbeak
heterocercal fin: a tail fin with unequal lobes in which the vertebral column turns upward into the larger lobe as in sharks
heterodactyl foot: a bird's foot having the first and second toes of each foot directed backward and the third and fourth forward
heteroploid: (genetics) an organism or cell having a chromosome number that is not an even multiple of the haploid chromosome number for that species
heteropterous insect: true bugs: insects whose forewings are membranous but have leathery tips
Heteroscelus incanus: tattler of Pacific coastal regions
heterostracan: extinct jawless fish with the anterior part of the body covered with bony plates; of the Silurian and Devonian
Hexagrammos decagrammus: common food and sport fish of western coast of North America
Hexanchus griseus: large primitive shark widely distributed in warm seas
hexapod: an animal having six feet
hide: body covering of a living animal
high stepper: a horse trained to lift its feet high off the ground while walking or trotting
Himantopus himantopus: stilt of Europe and Africa and Asia having mostly white plumage but with black wings
Himantopus himantopus leucocephalus: stilt of the southwest Pacific including Australia and New Zealand having mostly white plumage but with black wings and nape of neck
Himantopus mexicanus: stilt of southwestern United States to northern South America having black plumage extending from the head down the back of the neck
Himantopus novae-zelandiae: blackish stilt of New Zealand sometimes considered a color phase of the white-headed stilt
Himantopus stilt: long-legged three-toed black-and-white wading bird of inland ponds and marshes or brackish lagoons
hind: a female deer, especially an adult female red deer
hind: any of several mostly spotted fishes that resemble groupers
hind leg: the back limb of a quadruped
hind limb: a posterior appendage such as a leg or the homologous structure in other animals
hindfoot: a rear foot of a quadruped
hinny: hybrid offspring of a male horse and a female donkey or ass; usually sterile
Hippobosca equina: winged fly parasitic on horses
hippoboscid: bloodsucking dipterous fly parasitic on birds and mammals
Hippodamia convergens: a variety of ladybug
Hippoglossoides platessoides: large American food fish
Hippoglossus hippoglossus: largest United States flatfish
Hippoglossus stenolepsis: a righteye flounder found in the Pacific
Hippopotamus amphibius: massive thick-skinned herbivorous animal living in or around rivers of tropical Africa
Hippotragus niger: large black East African antelope with sharp backward-curving horns
Hipsurus caryi: Pacific coast fish
Hirudo medicinalis: large European freshwater leech formerly used for bloodletting
Hirundo nigricans: of Australia and Polynesia; nests in tree cavities
Hirundo pyrrhonota: North American swallow that lives in colonies and builds bottle-shaped mud nests on cliffs and walls
Hirundo rustica: common swallow of North America and Europe that nests in barns etc.
HIV: the virus that causes acquired immune deficiency syndrome (AIDS); it replicates in and kills the helper T cells
hock: tarsal joint of the hind leg of hoofed mammals; corresponds to the human ankle
hog: a sheep up to the age of one year; one yet to be sheared
hognose snake: harmless North American snake with upturned nose; may spread its head and neck or play dead when disturbed
Holocanthus tricolor: gold and black butterflyfish found from West Indies to Brazil
Holocentrus ascensionis: bright red fish of West Indies and Bermuda
Holocentrus bullisi: a squirrelfish found from South Carolina to Bermuda and Gulf of Mexico
Holocentrus coruscus: on reefs from Bermuda and Florida to northern South America
holocephalan: fish with high compressed head and a body tapering off into a long tail
holometabola: insects that undergo complete metamorphosis
Holothuria edulis: of warm coasts from Australia to Asia; used as food especially by Chinese
holothurian: echinoderm having a flexible sausage-shaped body, tentacles surrounding the mouth and tube feet; free-living mud feeders
Holstein-Friesian: a breed of dairy cattle from northern Holland
Homarus americanus: lobster of Atlantic coast of America
Homarus capensis: small lobster of southern Africa
Homarus vulgaris: lobster of Atlantic coast of Europe
homeotherm: an animal that has a body temperature that is relatively constant and independent of the environmental temperature
homer: pigeon trained to return home
hominid: a primate of the family Hominidae
hominoid: a primate of the superfamily Hominoidea
Homo erectus: extinct species of primitive hominid with upright stature but small brain
Homo habilis: extinct species of upright East African hominid having some advanced humanlike characteristics
Homo sapiens: the only surviving hominid; species to which modern man belongs; bipedal primate having language and ability to make and use complex tools; brain volume at least 1400 cc
Homo sapiens neanderthalensis: extinct robust human of Middle Paleolithic in Europe and western Asia
Homo sapiens sapiens: subspecies of Homo sapiens; includes all modern races
Homo soloensis: extinct primitive hominid of late Pleistocene; Java; formerly Javanthropus
homo: any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage
homocercal fin: symmetrical tail fin extending beyond the end of the vertebral column as in most bony fishes
Homona coffearia: small Indian moth infesting e.g. tea and coffee plants
homopteran: insects having membranous forewings and hind wings
honey eater: Australasian bird with tongue and bill adapted for extracting nectar
honey guide: small bird of tropical Africa and Asia; feeds on beeswax and honey and larvae
honeycreeper: small bright-colored tropical American songbird with a curved bill for sucking nectar
hood: (zoology) an expandable part or marking that resembles a hood on the head or neck of an animal
hoof: the foot of an ungulate mammal
hoof: the horny covering of the end of the foot in ungulate mammals
hoofed mammal: any of a number of mammals with hooves that are superficially similar but not necessarily closely related taxonomically
hookworm: parasitic bloodsucking roundworms having hooked mouth parts to fasten to the intestinal wall of human and other hosts
hoop snake: any of various harmless North American snakes that were formerly believed to take tail in mouth and roll along like a hoop
hoopoe: any of several crested Old World birds with a slender downward-curved bill
hoot owl: any owl that hoots as distinct from screeching
horn: any hard protuberance from the head of an organism that is similar to or suggestive of a horn
horn: one of the bony outgrowths on the heads of certain ungulates
hornbill: bird of tropical Africa and Asia having a very large bill surmounted by a bony protuberance; related to kingfishers
horned lizard: insectivorous lizard with hornlike spines on the head and spiny scales on the body; of western North America
horned owl: large owls having prominent ear tufts
hornet: large stinging paper wasp
horse's foot: the hoof of a horse
horseback: the back of a horse
horseleech: any of several large freshwater leeches
horseshoe bat: a bat of the family Rhinolophidae having a horseshoe-shaped leaf on the nose
horseshoe bat: any of numerous bats of the family Hipposideridae of northwest Africa or Philippines or Australia having a horseshoe-shaped leaf on the nose
host: an animal or plant that nourishes and supports a parasite; it does not benefit and is often harmed by the association
hound: any of several breeds of dog used for hunting typically having large drooping ears
housedog: a dog trained to guard a house
howler: monkey of tropical South American forests having a loud howling cry
HSV-1: a herpes virus that causes oral herpes
HSV-II: a herpes virus that can cause genital herpes
Hudson bay collared lemming: of northern Canada
human beings: all of the living human inhabitants of the earth
human papilloma virus: any of a group of papovaviruses associated with genital or oral carcinomas or a group associated with benign genital tumors
human T-cell leukemia virus-1: retrovirus causing T-cell leukemia
hummingbird: tiny American bird having brilliant iridescent plumage and long slender bills; wings are specialized for vibrating flight
Hungarian partridge: common European partridge
Hungarian pointer: Hungarian hunting dog resembling the Weimaraner but having a rich deep red coat
hunting dog: a dog used in hunting game
hunting spider: ground spider that hunts its prey instead of using a web
Hyaena brunnea: of southern Africa
Hyaena hyaena: of northern Africa and Arabia and India
hyaena: doglike nocturnal mammal of Africa and southern Asia that feeds chiefly on carrion
Hyalophora cecropia: North American silkworm moth; larvae feed on the leaves of forest trees
hydra: small tubular solitary freshwater hydrozoan polyp
Hydrobates pelagicus: sooty black petrel with white markings; of the northern Atlantic and Mediterranean
Hydrochoerus hydrochaeris: pig-sized tailless South American amphibious rodent with partly webbed feet; largest living rodent
Hydrodamalis gigas: extinct large sirenian mammal formerly found near the Asiatic coast of the Bering Sea
hydroid: colonial coelenterates having the polyp phase dominant
Hydromantes brunus: similar to Shasta salamander; lives in cliff crevices and taluses
Hydromantes shastae: primarily a cave dweller in the Mount Shasta area
Hyemoschus aquaticus: largest chevrotain; of marshy areas of west Africa
Hyla arenicolor: a small chiefly ground dweller that stays within easy jumping distance of water; of United States southwest and northern Mexico
Hyla crucifer: a small brown tree toad having a shrill call heard near wetlands of eastern United States and Canada in early spring
Hylactophryne augusti: of southwest United States and Mexico; call is like a dog's bark
Hylobates lar: smallest and most perfectly anthropoid arboreal ape having long arms and no tail; of southern Asia and East Indies
Hylocichla fuscescens: tawny brown North American thrush noted for its song
Hylocichla guttata: North American thrush noted for its complex and appealing song
Hylocichla mustelina: large thrush common in eastern American woodlands; noted for its melodious song
Hylophylax naevioides: a kind of antbird
hymenopter: insects having two pairs of membranous wings and an ovipositor specialized for stinging or piercing
Hynerpeton bassetti: fossil amphibian of the Devonian having well-developed forelimbs; found in Pennsylvania
Hypentelium nigricans: widely distributed in warm clear shallow streams
Hyperglyphe perciformis: blackish fish of New England waters
hypermastigote: flagellate symbiotic in the intestines of e.g. termites
Hyperoodon ampullatus: northern Atlantic beaked whale with a bulbous forehead
Hyphantria cunea: moth whose larvae are fall webworms
Hyphantria cunea: a variety of webworm
hypodermis: layer of cells that secretes the chitinous cuticle in e.g. arthropods
Hypsiglena torquata: nocturnal prowler of western United States and Mexico
Hypsiprymnodon moschatus: small kangaroo of northeastern Australia
Ibero-mesornis: sparrow-sized fossil bird of the Cretaceous period having a vestigial tail; found in Spain; considered possibly the third most primitive of all birds
ibis: wading birds of warm regions having long slender down-curved bills
Ibis ibis: any of several Old World birds of the genus Ibis
Ibizan Podenco: breed of slender agile medium-sized hound found chiefly in the Balearic Islands; said to have been bred originally by the Pharaohs of ancient Egypt
ichneumon fly: hymenopterous insect that resembles a wasp and whose larvae are parasitic on caterpillars and other insect larvae
ichthyosaur: any of several marine reptiles of the Mesozoic having a body like a porpoise with dorsal and tail fins and paddle-shaped limbs
ichthyosaurus: ichthyosaurs of the Jurassic
Ichyostega: early tetrapod amphibian found in Greenland
Ictalurus punctatus: freshwater food fish common throughout central United States
Icteria virens: American warbler noted for imitating songs of other birds
Icterus galbula: a kind of New World oriole
Icterus galbula bullockii: western subspecies of northern oriole
Icterus galbula galbula: eastern subspecies of northern oriole
Icterus spurius: the male is chestnut-and-black
Ictiobus niger: fish of the lower Mississippi
ictodosaur: intermediate in form between the therapsids and most primitive true mammals
Ictonyx frenata: muishond of northern Africa
Ictonyx striata: ferret-sized muishond often tamed
Iguana iguana: large herbivorous tropical American arboreal lizards with a spiny crest along the back; used as human food in Central America and South America
iguanid: lizards of the New World and Madagascar and some Pacific islands; typically having a long tail and bright throat patch in males
iguanodon: massive herbivorous bipedal dinosaur with a long heavy tail; common in Europe and northern Africa; early Cretaceous period
imago: an adult insect produced after metamorphosis
Inachis io: European butterfly having reddish-brown wings each marked with a purple eyespot
inchworm: small hairless caterpillar having legs on only its front and rear segments; mostly larvae of moths of the family Geometridae
Indian buffalo: upland buffalo of eastern Asia where true water buffaloes do not thrive; used for draft and milk
Indian cobra: a cobra of tropical Africa and Asia
Indian elephant: Asian elephant having smaller ears and tusks primarily in the male
Indian mongoose: keen-sighted viverrine of southern Asia about the size of a ferret; often domesticated
Indian pony: a small native range horse
Indian rat snake: enter buildings in pursuit of prey
Indri brevicaudatus: large short-tailed lemur of Madagascar having thick silky fur in black and white and fawn
infusorian: any member of the subclass Infusoria
insect: small air-breathing arthropod
insectivore: small insect-eating mainly nocturnal terrestrial or fossorial mammals
insectivore: any organism that feeds mainly on insects
instar: an insect or other arthropod between molts
intermediate host: a host that is used by a parasite in the course of its life cycle
intestinal flora: harmless microorganisms (as Escherichia coli) that inhabit the intestinal tract and are essential for its normal functioning
invertebrate: any animal lacking a backbone or notochord; the term is not used as a scientific classification
investment: outer layer or covering of an organ or part or organism
Iridoprocne bicolor: bluish-green-and-white North American swallow; nests in tree cavities
Irish setter: an Irish breed with a chestnut-brown or mahogany-red coat
Irish terrier: medium-sized breed with a wiry brown coat; developed in Ireland
Irish water spaniel: breed of large spaniels developed in Ireland having a heavy coat of liver-colored curls and a topknot of long curls and a nearly hairless tail
Irish wolfhound: large breed of hound with a rough thick coat
isopod: any of various small terrestrial or aquatic crustaceans with seven pairs of legs adapted for crawling
Istiophorus albicans: a kind of sailfish
Isurus glaucus: common blue-grey shark of southwest Pacific; sport and food fish
Isurus oxyrhincus: very swift active bluish shark found worldwide in warm waters; important game fish
Isurus paucus: similar to shortfin mako but darker blue
Italian bee: yellowish honeybee resembling the Carniolan bee in its habits
Italian greyhound: a toy dog developed from the greyhound
itch mite: whitish mites that attack the skin of humans and other animals
Ixobrychus exilis: small American bittern
Ixodes dammini: a northeastern tick now recognized as same species as Ixodes scapularis
Ixodes dentatus: usually does not bite humans; transmits Lyme disease spirochete to cottontail rabbits and wood rats
Ixodes neotomae: a tick that usually does not bite humans; transmits Lyme disease spirochete to dusky-footed wood rats
Ixodes pacificus: a tick that feeds on dusky-footed wood rat and bites humans; principal vector for Lyme disease in western United States especially northern California
Ixodes persulcatus: bites humans; a vector for Lyme disease spirochete
Ixodes ricinus: parasitic on sheep and cattle as well as humans; can transmit looping ill in sheep (acute viral disease of the nervous system); a vector for Lyme disease spirochete
Ixodes scapularis: parasitic on mice of genus Peromyscus and bites humans; principal vector for Lyme disease in eastern United States (especially New England); northern form was for a time known as Ixodes dammini (deer tick)
Ixodes spinipalpis: usually does not bite humans; transmits Lyme disease spirochete to cottontail rabbits and wood rats
Jabiru mycteria: large white stork of warm regions of the world especially America
jacamar: tropical American insectivorous bird having a long sharp bill and iridescent green or bronze plumage
jack: any of several fast-swimming predacious fishes of tropical to warm temperate seas
jack: male donkey
jackknife clam: marine clam having a long narrow curved thin shell
jackrabbit: large hare of western North America
Jaculus jaculus: a variety of jerboa
jaeger: rapacious seabird that pursues weaker birds to make them drop their prey
Japanese deer: small deer of Japan with slightly forked antlers
Japanese oyster: a large oyster native to Japan and introduced along the Pacific coast of the United States; a candidate for introduction in Chesapeake Bay
Japanese spaniel: breed of toy dogs originating in Japan having a silky black-and-white or red-and-white coat
jassid: a variety of leafhopper
jawfish: small large-mouthed tropical marine fishes common along sandy bottoms; males brood egg balls in their mouths; popular aquarium fishes
jay: crested largely blue bird
jellyfish: any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans
jennet: female donkey
jenny wren: any of several small active brown birds of the northern hemisphere with short upright tails; they feed on insects
jerboa: mouselike jumping rodent
jerboa kangaroo: brush-tailed rat kangaroo
jerboa rat: large Australian rat with hind legs adapted for leaping
Jersey: a breed of diary cattle developed on the island of Jersey
jird: gerbil of northern Africa
jointworm: larva of chalcid flies injurious to the straw of wheat and other grains
Jordanella floridae: a fish with a dark-blue back and whitish sides with red stripes; found in swamps and streams of Florida
jumping bristletail: wingless insect living in dark moist places as under dead tree trunks; they make erratic leaps when disturbed
jumping mouse: any of several primitive mouselike rodents with long hind legs and no cheek pouches; of woodlands of Eurasia and North America
jumping plant louse: small active cicada-like insect with hind legs adapted for leaping; feeds on plant juices
Junco hyemalis: common North American junco having grey plumage and eyes with dark brown irises
junco: small North American finch seen chiefly in winter
June beetle: any of various large usually brown North American leaf-eating beetles common in late spring; the larvae feed on roots of grasses etc.
jungle cock: male jungle fowl
jungle hen: female jungle fowl
Junin virus: the RNA virus that causes Argentine hemorrhagic fever; carried by rats and mice
Kakatoe galerita: white cockatoo with a yellow erectile crest
Kakatoe leadbeateri: white Australian cockatoo with roseate tinged plumage
Kamchatkan sea eagle: found on coasts of the northwestern Pacific
kangaroo: any of several herbivorous leaping marsupials of Australia and New Guinea having large powerful hind legs and a long thick tail
kangaroo mouse: leaping rodent of Australian desert areas
kangaroo rat: any of several rabbit-sized ratlike Australian kangaroos
Katsuwonus pelamis: fish whose flesh is dried and flaked for Japanese cookery; may be same species as skipjack tuna
katydid: large green long-horned grasshopper of North America; males produce shrill sounds by rubbing together special organs on the forewings
keeshond: a spitz-like dog having a shaggy greyish coat and tightly curled tail originating in Holland
kelp: large brown seaweeds having fluted leathery fronds
kelpie: an Australian sheepdog with pointed ears
Kerry blue terrier: an Irish breed of medium-sized terriers with a silky blue-grey coat
kid: young goat
kill: the body of an animal, or bodies of animals, killed by a person or another animal
killifish: small mostly marine warm-water carp-like schooling fishes; used as bait or aquarium fishes or in mosquito control
King Charles spaniel: a toy English spaniel with a black-and-tan coat; named after Charles II who popularized it
king snake: any of numerous nonvenomous North American constrictors; feed on other snakes and small mammals
kingdom Animalia: taxonomic kingdom comprising all living or extinct animals
kingdom Prokaryotae: prokaryotic bacteria and blue-green algae and various primitive pathogens; because of lack of consensus on how to divide the organisms into phyla informal names are used for the major divisions
kingdom Protoctista: in most modern classifications, replacement for the Protista; includes: Protozoa; Euglenophyta; Chlorophyta; Cryptophyta; Heterokontophyta; Rhodophyta; unicellular protists and their descendant multicellular organisms: regarded as distinct from plants and animals
kingfish: any of several food and game fishes of the drum family indigenous to warm Atlantic waters of the North American coast
kingfisher: nonpasserine large-headed bird with a short tail and long sharp bill; usually crested and bright-colored; feed mostly on fish
kinglet: small birds resembling warblers but having some of the habits of titmice
kit: young of any of various fur-bearing animals
kite: any of several small graceful hawks of the family Accipitridae having long pointed wings and feeding on insects and small animals
kitten: young domestic cat
kittiwake: small pearl-grey gull of northern regions; nests on cliffs and has a rudimentary hind toe
kitty: informal terms referring to a domestic cat
klebsiella: a genus of nonmotile rod-shaped Gram-negative enterobacteria; some cause respiratory and other infections
knee: joint between the femur and tibia in a quadruped; corresponds to the human knee
Kobus kob: an orange-brown antelope of southeast Africa
Kobus leche: tawny-colored African antelope inhabiting wet grassy plains; a threatened species
Kogia breviceps: small sperm whale of warm waters of both coasts of North America
Kogia simus: very small (to 8 feet) sperm whale of central coasts of Atlantic and Pacific
komondor: Hungarian breed of large powerful shaggy-coated white dog; used also as guard dog
koodoo: either of two spiral-horned antelopes of the African bush
krait: brightly colored venomous but nonaggressive snake of southeastern Asia and Malay peninsula
krill: shrimp-like planktonic crustaceans; major source of food for e.g. baleen whales
kuvasz: long-established Hungarian breed of tall light-footed but sturdy white dog; used also as a hunting dog
Kyphosus sectatrix: food and game fish around Bermuda and Florida; often follow ships
Labrador retriever: breed originally from Labrador having a short black or golden-brown coat
labyrinthodont: an amphibian of the superorder Labyrinthodontia
lace bug: small bug having body and wings covered with a lacy network of raised lines
Lacerta agilis: a common and widely distributed lizard of Europe and central Asia
Lacerta viridis: a common Eurasian lizard about a foot long
lacertid: Old World terrestrial lizard
lacewing: any of two families of insects with gauzy wings (Chrysopidae and Hemerobiidae); larvae feed on insect pests such as aphids
Lachnolaimus maximus: large wrasse of western Atlantic; head of male resembles a pig's snout
lactobacillus: a Gram-positive rod-shaped bacterium that produces lactic acid (especially in milk)
Lactobacillus acidophilus: a bacterium that is used to make yogurt and to supplement probiotics
Lactophrys quadricornis: trunkfish having hornlike spines over the eyes
lady beetle: small round bright-colored and spotted beetle that usually feeds on aphids and other insect pests
Lagodon rhomboides: similar to sea bream; small spiny-finned fish found in bays along the southeastern coast of the United States
Lagopus scoticus: reddish-brown grouse of upland moors of Great Britain
Lagostomus maximus: gregarious burrowing rodent larger than the chinchillas
lake salmon: Atlantic salmon confined to lakes of New England and southeastern Canada
Lakeland terrier: breed of wire-haired terrier originally from the Lake District of England and used for hunting
Lama guanicoe: wild llama
Lama pacos: domesticated llama with long silky fleece; believed to be a domesticated variety of the guanaco
Lama peruana: used in the Andes as a beast of burden and source of wool; considered a domesticated variety of the guanaco
lamb: young sheep
lambkin: a very young lamb
lamellicorn beetle: beetle having antennae with hard platelike terminal segments
Lamna nasus: voracious pointed-nose shark of northern Atlantic and Pacific
lamper eel: primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue
Lampris guttatus: from Nova Scotia to West Indies and Gulf of Mexico
Lampris regius: large elliptical brightly colored deep-sea fish of Atlantic and Pacific and Mediterranean
Lampropeltis getulus: widespread in United States except northern regions; black or brown with yellow bands
Lampropeltis triangulum: nonvenomous tan and brown king snake with an arrow-shaped occipital spot; southeastern ones have red stripes like coral snakes
lancet fish: large elongate scaleless oceanic fishes with sharp teeth and a long dorsal fin that resembles a sail
langur: slender long-tailed monkey of Asia
Lanius borealis: a butcherbird of northern North America
Lanius excubitor: a common European butcherbird
Lanius lucovicianus: a common shrike of southeastern United States having black bands around the eyes
Lanius ludovicianus excubitorides: a butcherbird of western North America; grey with white underparts
Lanius ludovicianus migrans: a shrike of central North America; winters in Texas and the southern Mississippi valley
lantern fly: large brightly marked tropical insect with a process like a snout that was formerly thought to emit light
lanternfish: small fish having rows of luminous organs along each side; some surface at night
Lanthanotus borneensis: a stout-bodied pleurodont lizard of Borneo
lapdog: a dog small and tame enough to be held in the lap
lapin: castrated male rabbit
lappet caterpillar: larva of a lappet moth
lappet: medium-sized hairy moths; larvae are lappet caterpillars
large poodle: the largest breed of poodle
larid: long-winged web-footed aquatic bird of the gull family
lark: any of numerous predominantly Old World birds noted for their singing
lark: North American songbirds having a yellow breast
lark: a songbird that lives mainly on the ground in open country; has streaky brown plumage
Larus argentatus: large gull of the northern hemisphere
Larus canus: the common gull of Eurasia and northeastern North America
Larus marinus: white gull having a black back and wings
Larus ridibundus: small black-headed European gull
larva: the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose
larvacean: any member of the class Larvacea
lasiocampid: medium-sized stout-bodied neutral-colored moths with comb-like antennae
Lasiurus borealis: North American bat of a brick or rusty red color with hairs tipped with white
Lassa virus: the RNA virus that causes Lassa fever
lateral line: sense organs of fish and amphibians; believed to detect pressure changes in the water
Lates calcarifer: a species of large perch noted for its sporting and eating qualities; lives in marine, estuary, and freshwater habitats
Latimeria chalumnae: fish thought to have been extinct since the Cretaceous period but found in 1938 off the coast of Africa
Latinae: a subfamily of the family Centropomidae
Latrodectus mactans: venomous New World spider; the female is black with an hourglass-shaped red mark on the underside of the abdomen
launce: very small silvery eellike schooling fishes that burrow into sandy beaches
laver: edible red seaweeds
laver: seaweed with edible translucent crinkly green fronds
layer: thin structure composed of a single thickness of cells
layer: a hen that lays eggs
leaf bug: small bright-colored insect that feeds on plant juices
leaf insect: tropical insect having a flattened leaflike body; common in southern Asia and the East Indies
leaf miner: any of various small moths or dipterous flies whose larvae burrow into and feed on leaf tissue especially of the family Gracilariidae
leaf roller: moth whose larvae form nests by rolling and tying leaves with spun silk
leaf-cutter: bee that cuts rounded pieces from leaves and flowers to line its nest
leaf-foot bug: large sap-sucking bug with leaflike expansions on the legs
leaf-nosed snake: any of various pale blotched snakes with a blunt snout of southwestern North America
leafhopper: small leaping insect that sucks the juices of plants
leafnose bat: bat having a leaflike flap at the end of the nose; especially of the families Phyllostomatidae and Rhinolophidae and Hipposideridae
leather carp: scaleless domestic carp
leatherfish: any of several brightly colored tropical filefishes
leatherjack: any of several New World tropical fishes having tiny embedded scales
leatherjacket: tough-skinned larva of certain crane flies
Lebistes reticulatus: small freshwater fish of South America and the West Indies; often kept in aquariums
lefteye flounder: flatfishes with both eyes on the left side of the head
Legionella pneumophilia: the motile aerobic rod-shaped Gram-negative bacterium that thrives in central heating and air conditioning systems and can cause Legionnaires' disease
legless lizard: degenerate wormlike burrowing lizard of California closely related to alligator lizards
Leipoa ocellata: Australian mound bird; incubates eggs naturally in sandy mounds
lemming: any of various short-tailed furry-footed rodents of circumpolar distribution
Lemmus: lemmings
Lemmus trimucronatus: of northwestern Canada and Alaska
lemur: large-eyed arboreal prosimian having foxy faces and long furry tails
Leonberg: a large dog (usually with a golden coat) produced by crossing a St Bernard and a Newfoundland
leoncita: small South American marmoset with silky fur and long nonprehensile tail
Leontocebus oedipus: South American tamarin with a tufted head
Leontocebus rosalia: golden South American monkey with long soft hair forming a mane
leopard lizard: any of several large lizards with many dark spots; of western United States and northern Mexico
leopardess: female leopard
Lepas fascicularis: stalked barnacle that attaches to ship bottoms or floating timbers
Lepidochelys kempii: grey sea turtle of the Atlantic and Gulf Coasts of North America
Lepidochelys olivacea: olive-colored sea turtle of tropical Pacific and Indian and the southern Atlantic oceans
Lepidocybium flavobrunneum: large snake mackerel with rings like spectacles around its eyes
lepidopteran: insect that in the adult state has four wings more or less covered with tiny scales
Lepisma saccharina: silver-grey wingless insect found in houses feeding on book bindings and starched clothing
Lepisosteus osseus: primitive predaceous North American fish covered with hard scales and having long jaws with needlelike teeth
Lepomis gibbosus: small brilliantly colored North American sunfish
Lepomis macrochirus: important edible sunfish of eastern and central United States
Lepomis punctatus: inhabits streams from South Carolina to Florida; esteemed panfish
leporid: rabbits and hares
Leptinotarsa decemlineata: black-and-yellow beetle that feeds in adult and larval stages on potato leaves; originally of eastern Rocky Mountains; now worldwide
leptocephalus: slender transparent larva of eels and certain fishes
leptodactylid: toothed frogs: terrestrial or aquatic or arboreal
Leptodactylus pentadactylus: large toothed frog of South America and Central America resembling the bullfrog
Leptoptilus crumeniferus: large African black-and-white carrion-eating stork; its downy underwing feathers are used to trim garments
Leptoptilus dubius: large Indian stork with a military gait
leptospira: important pathogens causing Weil's disease or canicola fever
Leptotyphlops humilis: burrows among roots of shrubs and beneath rocks in desert and rocky hillside areas and beach sand of western United States
Lepus americanus: large large-footed North American hare; white in winter
Lepus arcticus: a large hare of northern North America; it is almost completely white in winter
Lepus californicus: the common jackrabbit of grasslands and open areas of western United States; has large black-tipped ears and black streak on the tail
Lepus europaeus: large hare introduced in North America; does not turn white in winter
Lepus townsendi: largest hare of northern plains and western mountains of United States; brownish-grey in summer and pale grey in winter; tail nearly always all white
lerot: dormouse of southern Europe and northern Africa
lesser ape: gibbons and siamangs
Leuciscus cephalus: European freshwater game fish with a thick spindle-shaped body
Leuciscus leuciscus: small European freshwater fish with a slender bluish-green body
leucocytozoan: parasitic in birds
leveret: a young hare especially one in its first year
Lhasa apso: a breed of terrier having a long heavy coat raised in Tibet as watchdogs
Lichanura trivirgata: boa of rocky desert of southwestern United States
liger: offspring of a male lion and a female tiger
Limanda ferruginea: American flounder having a yellowish tail
Lime disease spirochete: cause of Lyme disease; transmitted primarily by ticks of genus Ixodes
Limenitis archippus: showy American butterfly resembling the monarch but smaller
Limenitis arthemis: North American butterfly with blue-black wings crossed by a broad white band
Limenitis astyanax: similar to the banded purple but with red spots on underwing surfaces
Limenitis camilla: Eurasian butterfly with brown wings and white markings
limicoline bird: any of numerous wading birds that frequent mostly seashores and estuaries
Limnocryptes minima: a small short-billed Old World snipe
Limnodromus griseus: a dowitcher with a grey back
Limnodromus scolopaceus: a dowitcher with a red breast
Limosa haemastica: New World godwit
limpet: any of various usually marine gastropods with low conical shells; found clinging to rocks in littoral areas
Lincoln: long-wooled mutton sheep originally from Lincolnshire
ling: American hakes
lion cub: a young lion
lioness: a female lion
lionet: a small or young lion
lionfish: brightly striped fish of the tropical Pacific having elongated spiny fins
Liopelma hamiltoni: primitive New Zealand frog with four unwebbed toes on forefeet and five on hind feet
lip: either the outer margin or the inner margin of the aperture of a gastropod's shell
Liparis liparis: small tadpole-shaped cold-water fishes with pelvic fins forming a sucker; related to lumpfish
Liposcelis divinatorius: minute wingless psocopterous insects injurious to books and papers
Lippizaner: a compact and sturdy saddle horse that is bred and trained in Vienna; smart and docile and excellent for dressage
listeria: any species of the genus Listeria
Listeria monocytogenes: the type species of the genus Listeria; can cause meningitis, encephalitis, septicemia, endocarditis, abortion, abscesses, listeriosis
Litocranius walleri: slender East African antelope with slim neck and backward-curving horns
littleneck: a young quahog
live-bearer: small usually brightly-colored viviparous surface-feeding fishes of fresh or brackish warm waters; often used in mosquito control
liver chestnut: a solid dark brown horse
liver-spotted dalmatian: a brown-spotted dalmatian
lizard: relatively long-bodied reptile with usually two pairs of legs and a tapering tail
lizardfish: tropical fishes with large mouths in lizard-like heads; found worldwide
llama: wild or domesticated South American cud-chewing animal related to camels but smaller and lacking a hump
loach: slender freshwater fishes of Eurasia and Africa resembling catfishes
lobate foot: a bird's foot having separate toes each with membranous flaps along the sides
Lobipes lobatus: breeds in Arctic regions of Old and New Worlds; large flocks often seen far out at sea
Lobotes surinamensis: tripletail found from Cape Cod to northern South America
lobster: any of several edible marine crustaceans of the families Homaridae and Nephropsidae and Palinuridae
lobworm: marine worms having a row of tufted gills along each side of the back; often used for fishing bait
locust: migratory grasshoppers of warm regions having short antennae
Locusta migratoria: Old World locust that travels in vast swarms stripping large areas of vegetation
Lofortyx californicus: plump chunky bird of coastal California and Oregon
loin: either side of the backbone between the hipbone and the ribs in humans as well as quadrupeds
loligo: somewhat flattened cylindrical squid
long-eared bat: any of various Old or New World bats having very long ears
long-horned beetle: long-bodied beetle having very long antennae
long-horned grasshopper: grasshoppers with long threadlike antennae and well-developed stridulating organs on the forewings of the male
longwool: a domestic long-wool sheep
Lophius Americanus: fishes having large mouths with a wormlike filament attached for luring prey
Lophodytes cucullatus: small North American duck with a high circular crest on the male's head
Lopholatilus chamaeleonticeps: yellow-spotted violet food fish of warm deep waters
lorica: a hard protective sheath (as secreted by certain protoctists, for example)
lorikeet: any of various small lories
Loris gracilis: slim-bodied lemur of southern India and Sri Lanka
lory: small brightly colored Australasian parrots having a brush-tipped tongue for feeding on nectar and soft fruits
Lota lota: elongate freshwater cod of northern Europe and Asia and North America having barbels around its mouth
louse: any of several small insects especially aphids that feed by sucking the juices from plants
louse: wingless usually flattened bloodsucking insect parasitic on warm-blooded animals
lovebird: small African parrot noted for showing affection for their mates
Loxia curvirostra: finch with a bill whose tips cross when closed
Loxodonta africana: an elephant native to Africa having enormous flapping ears and ivory tusks
Loxostege similalis: moth whose larvae are garden webworms
Loxostege similalis: a variety of webworm
Lucy: incomplete skeleton of female found in eastern Ethiopia in 1974
Lumpenus lumpretaeformis: found in Arctic and northern Atlantic waters
lumpsucker: any of several very small lumpfishes
Lunda cirrhata: northern Pacific puffin having a large yellow plume over each eye
lungfish: air-breathing fish having an elongated body and fleshy paired fins; certain species construct mucus-lined mud coverings in which to survive drought
lungless salamander: mostly terrestrial salamanders that breathe through their thin moist skin; lay eggs in moist places on land; rarely enter water
Luscinia luscinia: large nightingale of eastern Europe
Luscinia megarhynchos: European songbird noted for its melodious nocturnal song
Lutjanus analis: similar to and often marketed as `red snapper'
Lutjanus apodus: food fish of warm Caribbean and Atlantic waters
Lutjanus blackfordi: an esteemed food fish with pinkish red head and body; common in the Atlantic coastal waters of North America and the Gulf of Mexico
Lutjanus griseus: found in shallow waters off the coast of Florida
Lutra canadensis: sociable aquatic animal widely distributed along streams and lake borders in North America
Luvarus imperialis: large silvery fish found worldwide in warm seas but nowhere common; resembles a whale and feeds on plankton
Lycaena hypophlaeas: common copper butterfly of central and eastern North America
lycaenid: any of various butterflies of the family Lycaenidae
lygaeid: a true bug: usually bright-colored; pest of cultivated crops and some fruit trees
lygus bug: vector of viral plant diseases
Lygus lineolaris: widespread plant and fruit pest
Lymantria dispar: European moth introduced into North America; a serious pest of shade trees
lymantriid: dull-colored moth whose larvae have tufts of hair on the body and feed on the leaves of many deciduous trees
lymphocytic choriomeningitis virus: the RNA virus that causes lymphocytic choriomeningitis; infects mice and monkeys and dogs and guinea pigs and human beings
Lynx canadensis: of northern North America
Lynx caracal: of deserts of northern Africa and southern Asia
Lynx lynx: of northern Eurasia
Lynx pardina: of southern Europe
Lynx rufus: small lynx of North America
lyre snake: mildly venomous snake with a lyre-shaped mark on the head; found in rocky areas from southwestern United States to Central America
lyrebird: Australian bird that resembles a pheasant; the courting male displays long tail feathers in a lyre shape
Lyrurus mlokosiewiczi: a black grouse of western Asia
lyssavirus: a neurotropic non-arbovirus of the family Rhabdoviridae that causes rabies
Macaca irus: monkey of southeast Asia, Borneo and the Philippines
Macaca mulatta: of southern Asia; used in medical research
Macaca radiata: Indian macaque with a bonnet-like tuft of hair
Macaca sylvana: tailless macaque of rocky cliffs and forests of northwestern Africa and Gibraltar
macaque: short-tailed monkey of rocky regions of Asia and Africa
macaw: long-tailed brilliantly colored parrot of Central America and South America; among the largest and showiest of parrots
Machupo virus: the RNA virus that causes Bolivian hemorrhagic fever; carried by rats and mice
mackerel: any of various fishes of the family Scombridae
mackerel shark: fierce pelagic and oceanic sharks
Macrocephalon maleo: Celebes megapode that lays eggs in holes in sandy beaches
Macrocheira kaempferi: very large deep-water Japanese crab
Macroclemys temmincki: large species having three ridges on its back; found in southeastern United States
Macrodactylus subspinosus: common North American beetle: larvae feed on roots and adults on leaves and flowers of e.g. rose bushes or apple trees or grape vines
Macronectes giganteus: large brownish petrel chiefly of Antarctic seas
Macropus agiles: a small wallaby having a height of 30 inches
Macropus giganteus: very large greyish-brown Australian kangaroo formerly abundant in open wooded areas
Macrotis lagotis: bandicoot with leathery ears like a rabbit
Macrotus californicus: large-eared greyish bat of southern California and northwestern Mexico
Macrozoarces americanus: common along northeastern coast of North America
Madagascar cat: small lemur having its tail barred with black
madrepore: corals having calcareous skeletons aggregations of which form reefs and islands
maggot: the larva of the housefly and blowfly commonly found in decaying organic matter
Magicicada septendecim: North American cicada; appears in great numbers at infrequent intervals because the nymphs take 13 to 17 years to mature
magpie: long-tailed black-and-white crow that utters a raucous chattering call
Makaira albida: small marlin (to 180 pounds) of western Atlantic
Makaira marlina: large game fish in the Pacific Ocean; may reach 1000 pounds
Makaira mitsukurii: Pacific food and game fish marked with dark blue vertical stripes
Makaira nigricans: largest marlin; may reach 2000 pounds; found worldwide in warm seas
mako: powerful mackerel shark of the Atlantic and Pacific
Malaclemys centrata: of marshes along Atlantic and Gulf Coasts of United States
malacopterygian: any fish of the superorder Malacopterygii
Malacosoma americana: moth whose larvae are tent caterpillars
Malacosoma disstria: moth whose gregarious larvae spin webs resembling carpets
Malacosoma disstria: larvae of a gregarious North American moth that spins a web resembling a carpet rather than a tent; serious defoliator of deciduous trees
malacostracan crustacean: a major subclass of crustaceans
malaria mosquito: transmits the malaria parasite
male: an animal that produces gametes (spermatozoa) that can fertilize female gametes (ova)
male horse: the male of species Equus caballus
malinois: fawn-colored short-haired sheepdog
mallee hen: adult female mallee fowl
Malopterurus electricus: freshwater catfish of the Nile and tropical central Africa having an electric organ
Maltese cat: a term applied indiscriminately in the United States to any short-haired bluish-grey cat
Maltese terrier: breed of toy dogs having a long straight silky white coat
mamba: arboreal snake of central and southern Africa whose bite is often fatal
mammal family: a family of mammals
mammal genus: a genus of mammals
mammal Semnopithecus: langurs
mammal: any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk
mammoth: any of numerous extinct elephants widely distributed in the Pleistocene; extremely large with hairy coats and long upcurved tusks
Mammuthus columbi: a variety of mammoth
Mammuthus primigenius: very hairy mammoth common in colder portions of the northern hemisphere
mamo: black honeycreepers with yellow feathers around the tail; now extinct
manakin: any of numerous small bright-colored birds of Central America and South America having short bills and elaborate courtship behavior
Manchester terrier: a breed of short-haired rat terrier with a black-and-tan coat that was developed in Manchester, England
Mandrillus leucophaeus: similar to the mandrill but smaller and less brightly colored
Mandrillus sphinx: baboon of west Africa with a bright red and blue muzzle and blue hindquarters
Manduca quinquemaculata: moth whose larvae are tomato hornworms
Manduca quinquemaculata: large green white-striped hawkmoth larva that feeds on tomato and potato plants; similar to tobacco hornworm
Manduca sexta: moth whose larvae are tobacco hornworms
Manduca sexta: large green white-striped hawkmoth larva that feeds on tobacco and related plants; similar to tomato hornworm
mane: long coarse hair growing from the crest of the animal's neck
mangabey: large agile arboreal monkey with long limbs and tail and white upper eyelids
maniraptor: advanced carnivorous theropod
Manta birostris: largest manta (to 22 feet across wings); found worldwide but common in Gulf of Mexico and along southern coasts of United States; primarily oceanic
mantid: predacious long-bodied large-eyed insect of warm regions; rests with forelimbs raised as in prayer
mantis crab: tropical marine burrowing crustaceans with large grasping appendages
mantis prawn: a kind of mantis shrimp
Mantis religioso: the common mantis
mantispid: insect that resembles a mantis; larvae are parasites in the nests of spiders and wasps
Mantophasmatodea: an order of insect identified in 2002 in a 45 million year old piece of amber from the Baltic region
Manx cat: a short-haired tailless breed of cat believed to originate on the Isle of Man
maori hen: flightless New Zealand rail of thievish disposition having short wings each with a spur used in fighting
mapinguari: supposed human-sized sloth-like creature reportedly sighted by Indians in the Amazon rain forest
marabou: the downy feathers of marabou storks are used for trimming garments
Marburg virus: a filovirus that causes Marburg disease; carried by animals; can be used as a bioweapon
Marco Polo's sheep: Asiatic wild sheep with exceptionally large horns; sometimes considered a variety of the argali (or Ovis ammon)
marine animal: any of numerous animals inhabiting the sea including e.g. fishes and molluscs and many mammals
marine mussel: marine bivalve mollusk having a dark elongated shell; live attached to solid objects especially in intertidal zones
marine turtle: any of various large turtles with limbs modified into flippers; widely distributed in warm seas
marlin: large long-jawed oceanic sport fishes; related to sailfishes and spearfishes; not completely cold-blooded i.e. able to warm their brains and eyes
marmoset: small soft-furred South American and Central American monkey with claws instead of nails
marmot: stocky coarse-furred burrowing rodent with a short bushy tail found throughout the northern hemisphere; hibernates in winter
Marmota caligata: large North American mountain marmot
Marmota flaviventris: heavy-bodied yellowish-brown marmot of rocky areas of western North America
Marmota monax: reddish brown North American marmot
marsh wren: a wren of the genus Cistothorus that frequents marshes
marsupial mouse: any of numerous small sharp-nosed insectivorous marsupials superficially resembling mice or rats
marsupial: mammals of which the females have a pouch (the marsupium) containing the teats where the young are fed and carried
marten: agile slender-bodied arboreal mustelids somewhat larger than weasels
Martes americana: valued for its fur
Martes foina: Eurasian marten having a brown coat with pale breast and throat
Martes martes: dark brown marten of northern Eurasian coniferous forests
Martes pennanti: large dark brown North American arboreal carnivorous mammal
Martes zibellina: marten of northern Asian forests having luxuriant dark brown fur
martin: any of various swallows with squarish or slightly forked tail and long pointed wings; migrate around Martinmas
Maryland yellowthroat: an American warbler
mason bee: any of numerous solitary bees that build nests of hardened mud and sand
mason wasp: solitary wasp that constructs nests of hardened mud or clay for the young
mason wasp: any of various solitary wasps that construct nests of hardened mud for their young
Masticophis bilineatus: both terrestrial and arboreal snake of United States southwest
Masticophis flagellum: a whipsnake of southern United States and Mexico; tail resembles a braided whip
Masticophis lateralis: a whipsnake of scrublands and rocky hillsides
mastiff: an old breed of powerful deep-chested smooth-coated dog used chiefly as a watchdog and guard dog
mastiff bat: a soft-furred chocolate-brown bat with folded ears and small wings; often runs along the ground
Mastigoproctus giganteus: large whip-scorpion of Mexico and southern United States that emits a vinegary odor when alarmed
mastodon: extinct elephant-like mammal that flourished worldwide from Miocene through Pleistocene times; differ from mammoths in the form of the molar teeth
Mastotermes darwiniensis: Australian termite; sole living species of Mastotermes; called a living fossil; apparent missing link between cockroaches and termites
Mastotermes electrodominicus: extinct termite found in amber in the Dominican Republic
Mastotermes electromexicus: an extinct termite found in amber in southern Mexico
maverick: an unbranded range animal (especially a stray calf); belongs to the first person who puts a brand on it
Mayetiola destructor: small fly whose larvae damage wheat and other grains
mealworm: the larva of beetles of the family Tenebrionidae
mealy bug: scalelike plant-eating insect coated with a powdery waxy secretion; destructive especially of fruit trees
mecopteran: any of various carnivorous insects of the order Mecoptera
Mediterranean flour moth: small moth whose larvae damage stored grain and flour
Mediterranean fruit fly: small black-and-white fly that damages citrus and other fruits by implanting eggs that hatch inside the fruit
Mediterranean water shrew: a type of water shrew
medusa: one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles
meerkat: a mongoose-like viverrine of South Africa having a face like a lemur and only four toes
Megaderma lyra: large carnivorous Old World bat with very large ears
Megalobatrachus maximus: large (up to more than three feet) edible salamander of Asia
megalosaur: gigantic carnivorous bipedal dinosaur of the Jurassic or early Cretaceous in Europe
megapode: large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs
Megaptera novaeangliae: large whalebone whale with long flippers noted for arching or humping its back as it dives
megatherian: a large extinct ground sloth
Melanerpes erythrocephalus: black-and-white North American woodpecker having a red head and neck
Melanitta nigra: a variety of scoter
Melanogrammus aeglefinus: important food fish on both sides of the Atlantic; related to cod but usually smaller
Melanotis caerulescens: mockingbird of Mexico
Meleagris gallopavo: large gallinaceous bird with fan-shaped tail; widely domesticated for food
Mellivora capensis: nocturnal badger-like carnivore of wooded regions of Africa and southern Asia
Melolontha melolontha: any of various large European beetles destructive to vegetation as both larvae and adult
melolonthid beetle: any of various beetles of the family (or subfamily) Melolonthidae
Melophagus Ovinus: wingless fly that is an external parasite on sheep and cattle
Melopsittacus undulatus: small Australian parakeet usually light green with black and yellow markings in the wild but bred in many colors
Melospiza georgiana: North American finch of marshy area
Melospiza melodia: small songbird common in North America
Melursus ursinus: common coarse-haired long-snouted bear of south-central Asia
Menippe mercenaria: large edible crab of the southern coast of the United States (particularly Florida)
Menopon palladum: a louse parasitic on poultry
Menticirrhus americanus: whiting of the southeastern coast of North America
Menticirrhus littoralis: a dull silvery whiting of southern Atlantic and Gulf Coasts of the United States
Menticirrhus saxatilis: whiting of the east coast of United States; closely resembles king whiting
Menticirrhus undulatus: bluish-grey whiting of California coast
Mephitis macroura: of Mexico and southernmost parts of southwestern United States
Mephitis mephitis: most common and widespread North American skunk
Mercenaria mercenaria: an edible American clam; the heavy shells were used as money by some American Indians
Mergus albellus: smallest merganser and most expert diver; found in northern Eurasia
Mergus merganser: common merganser of Europe and North America
Mergus merganser americanus: common North American diving duck considered a variety of the European goosander
Mergus serrator: widely distributed merganser of America and Europe
merino: white sheep originating in Spain and producing a heavy fleece of exceptional quality
Meriones longifrons: southern European gerbil
Meriones unguiculatus: a gerbil that is popular as a pet
Merlangus merlangus: a food fish of the Atlantic waters of Europe resembling the cod; sometimes placed in genus Gadus
Merluccius bilinearis: found off Atlantic coast of North America
merozoite: a cell that arises from the asexual division of a parent sporozoan during its life cycle
mesenchyme: mesodermal tissue that forms connective tissue and blood and smooth muscles
mesoblast: the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue
Mesocricetus auratus: small light-colored hamster often kept as a pet
mesohippus: North American three-toed Oligocene animal; probably not directly ancestral to modern horses
metamere: one of a series of similar body segments into which some animals are divided longitudinally
metatherian: primitive pouched mammals found mainly in Australia and the Americas
metazoan: any animal of the subkingdom Metazoa; all animals except protozoans and sponges
methanogen: archaebacteria found in anaerobic environments such as animal intestinal tracts or sediments or sewage and capable of producing methane; a source of natural gas
Mexican beaded lizard: lizard with black and yellowish beadlike scales; of western Mexico
Mexican hairless: any of an old breed of small nearly hairless dogs of Mexico
Mexican pocket mouse: large pocket mouse of Mexico
Mickey Mouse: a fictional mouse created in animated film strips by Walt Disney
Micromyx minutus: small reddish-brown Eurasian mouse inhabiting e.g. cornfields
microorganism: any organism of microscopic size
Micropogonias undulatus: a silvery-bodied croaker with dark markings and tiny barbels
Micropterus dolomieu: a variety of black bass; the angle of the jaw falls below the eye
Micropterus pseudoplites: a variety of black bass
Micropterus salmoides: a large black bass; the angle of the jaw falls behind the eye
microsporidian: parasite of arthropods and fishes that invade and destroy host cells
Microstomus kitt: European flatfish highly valued as food
Microtus ochrogaster: typical vole of the extended prairie region of central United States and southern Canada
Microtus pennsylvaticus: widely distributed in grasslands of northern United States and Canada
Microtus richardsoni: of western North America
Micruroides euryxanthus: ranges from Central America to southwestern United States
Micrurus fulvius: ranges from Central America to southeastern United States
midge: minute two-winged mosquito-like fly lacking biting mouthparts; appear in dancing swarms especially near water
Mighty Mouse: a fictional mouse endowed with great strength and courage
migrator: an animal (especially birds and fish) that travels between different habitats at particular times of the year
migratory grasshopper: serious pest of grain-growing and range areas of central and western United States
milking shorthorn: breed evolved from shorthorn beef cattle
millepede: any of numerous herbivorous nonpoisonous arthropods having a cylindrical body of 20 to 100 or more segments most with two pairs of legs
miller's-thumb: small freshwater sculpin of Europe and North America
miller: any of various moths that have powdery wings
milt: seminal fluid produced by male fish
Milvus migrans: dark Old World kite feeding chiefly on carrion
Mimus polyglotktos: long-tailed grey-and-white songbird of the southern United States able to mimic songs of other birds
mina: tropical Asian starlings
miniature pinscher: small German version of a Doberman pinscher
miniature poodle: a breed of small poodles
miniature schnauzer: a small schnauzer
mink: slender-bodied semiaquatic mammal having partially webbed feet; valued for its fur
Minnie Mouse: the partner of Mickey Mouse
mirror carp: domestic carp with some large shining scales
mite: any of numerous very small to minute arachnids often infesting animals or plants or stored foods
moa: extinct flightless bird of New Zealand
Mobula hypostoma: small manta (to 4 feet) that travels in schools
mocking thrush: thrush-like American songbird able to mimic other birdsongs
mojarra: small silvery schooling fishes with protrusible mouths found in warm coastal waters
moke: British informal for donkey
Mola lanceolata: caudal fin has a central projection
mole: small velvety-furred burrowing mammal having small eyes and fossorial forefeet
mole cricket: digs in moist soil and feeds on plant roots
mole rat: furry short-limbed tailless rodent resembling a true mole in habits and appearance; of eastern Europe and Middle East
mole rat: African rodent resembling a mole in habits and appearance
mollie: popular aquarium fish
mollusc: invertebrate having a soft unsegmented body usually enclosed in a shell
mollusk family: a family of mollusks
mollusk genus: a genus of mollusks
moloch: any lizard of the genus Moloch
Moloch horridus: desert lizard that feeds on ants
molter: an animal (especially birds and arthropods and reptiles) that periodically shed their outer layer (feathers or cuticle or skin or hair)
Molva molva: elongated marine food fish of Greenland and northern Europe; often salted and dried
momot: tropical American bird resembling a blue jay and having greenish and bluish plumage
monad: (biology) a single-celled microorganism (especially a flagellate protozoan)
monal: brilliantly colored pheasant of southern Asia
moneran: organisms that typically reproduce by asexual budding or fission and whose nutritional mode is absorption or photosynthesis or chemosynthesis
mongoose: agile grizzled Old World viverrine; preys on snakes and rodents
monitor: any of various large tropical carnivorous lizards of Africa and Asia and Australia; fabled to warn of crocodiles
monkey: any of various long-tailed primates (excluding the prosimians)
Monodon monoceros: small Arctic whale the male having a long spiral ivory tusk
monohybrid: a hybrid produced by crossing parents that are homozygous except for a single gene locus that has two alleles (as in Mendel's experiments with garden peas)
Monomorium minimum: tiny glossy black ant; nests outdoors but invades houses for food
Monomorium pharaonis: small red ant of warm regions; a common household pest
Mononychus olecranus: a turkey-sized long-legged fossil 75 million years old found in the Gobi Desert having bird-like fused wrist bones and keeled breastbone and a long tail resembling a dinosaur's; short forelimbs end in a single claw instead of wings; classification as bird or dinosaur is in dispute
monoplane flying fish: having only pectoral fins enlarged
monster: (medicine) a grossly malformed and usually nonviable fetus
Montagu's harrier: brownish European harrier
moon shell: marine gastropods having smooth rounded shells that form short spires
moorcock: male red grouse
moorhen: female red grouse
moray: family of brightly colored voracious eels of warm coastal waters; generally nonaggressive to humans but larger species are dangerous if provoked
Morelia spilotes variegatus: Australian python with a variegated pattern on its back
Morgan: an American breed of small compact saddle horses
Morlett's crocodile: a variety of crocodile
Morone americana: small silvery food and game fish of eastern United States streams
Morone interrupta: North American freshwater bass resembling the larger marine striped bass
morula: a solid mass of blastomeres that forms when the zygote splits; develops into the blastula
Moschus moschiferus: small heavy-limbed upland deer of central Asia; male secretes valued musk
mosquito: two-winged insect whose female has a long proboscis to pierce the skin and suck the blood of humans and animals
moth: typically crepuscular or nocturnal insect having a stout body and feathery or hairlike antennae
Mother Carey's chicken: medium-sized storm petrel
mother hen: a hen with chicks
mount: a lightweight horse kept for riding only
mountain chinchilla: a rodent native to the mountains of Chile and Peru and now bred in captivity
mountain paca: rodent of mountains of western South America
mountain sheep: any wild sheep inhabiting mountainous regions
mouse: any of numerous small rodents typically resembling diminutive rats having pointed snouts and small ears on elongated bodies with slender usually hairless tails
mouse-eared bat: a carnivorous bat with ears like a mouse
mouser: a cat proficient at mousing
mouthbreeder: any of various fishes that carry their eggs and their young in their mouths
mouthpart: any part of the mouth of an insect or other arthropod especially one adapted to a specific way of feeding
mud dauber: wasp that constructs mud cells on a solid base in which females place eggs laid in paralyzed insect larvae
mud turtle: bottom-dwelling freshwater turtle inhabiting muddy rivers of North America and Central America
mudder: a racehorse that runs well on a muddy racetrack
mudskipper: found in tropical coastal regions of Africa and Asia; able to move on land on strong pectoral fins
Mugil cephalus: most important commercial mullet in eastern United States
Mugil curema: silvery mullet of Atlantic and Pacific coasts
Mugil liza: similar to the striped mullet and takes its place in the Caribbean region
muishond: southern African weasel
mule: hybrid offspring of a male donkey and a female horse; usually sterile
mullet: bottom dwelling marine warm water fishes with two barbels on the chin
Mulloidichthys martinicus: schooling goatfish; greyish with yellow stripe
Mullus auratus: body bright scarlet with 2 yellow to reddish strips on side
Mullus surmuletus: brightly colored tropical fishes with chin barbels
murine: a rodent that is a member of the family Muridae
murre: black-and-white diving bird of northern seas
Mus musculus: brownish-grey Old World mouse now a common household pest worldwide
Musca domestica: common fly that frequents human habitations and spreads many diseases
Muscardinus avellanarius: a variety of dormouse
Muscicapa striata: common European woodland flycatcher with greyish-brown plumage
Muscivora-forficata: grey flycatcher of the southwestern United States and Mexico and Central America having a long forked tail and white breast and salmon and scarlet markings
mushroom coral: flattened disk-shaped stony coral (usually solitary and unattached)
musk hog: nocturnal gregarious pig-like wild animals of North America and South America
musk turtle: small freshwater turtle having a strong musky odor
mussel: marine or freshwater bivalve mollusk that lives attached to rocks etc.
mussel shrimp: tiny marine and freshwater crustaceans with a shrimp-like body enclosed in a bivalve shell
mustang: small hardy range horse of the western plains descended from horses brought by the Spanish
Mustela erminea: mustelid of northern hemisphere in its white winter coat
Mustela frenata: the common American weasel distinguished by large size and black-tipped tail
Mustela nigripes: musteline mammal of prairie regions of United States; nearly extinct
Mustela putorius: dark brown mustelid of woodlands of Eurasia that gives off an unpleasant odor when threatened
Mustela vison: usually rich dark brown
mustelid: fissiped fur-bearing carnivorous mammals
Mustelus mustelus: smooth dogfish of European coastal waters
mutant: an animal that has undergone mutation
muzzle: forward projecting part of the head of certain animals; includes the jaws and nose
Mya arenaria: an edible clam with thin oval-shaped shell found in coastal regions of the United States and Europe
mycobacteria: rod-shaped bacteria some saprophytic or causing diseases
Mycobacterium leprae: cause of leprosy
Mycobacterium tuberculosis: cause of tuberculosis
mycoplasma: any of a group of small parasitic bacteria that lack cell walls and can survive without oxygen; can cause pneumonia and urinary tract infection
Mycteria americana: an American stork that resembles the true ibises in having a downward-curved bill; inhabits wooded swamps of New World tropics
Mycteroperca bonaci: large dark grouper with a thick head and rough scales
mylodon: large (bear-sized) extinct edentate mammal of the Pleistocene in South America
mylodontid: a variety of extinct edentate
Myocastor coypus: aquatic South American rodent resembling a small beaver; bred for its fur
Myotis leucifugus: the small common North American bat; widely distributed
Myotis velifer: small bat of southwest United States that lives in caves etc.
myriapod: general term for any terrestrial arthropod having an elongated body composed of many similar segments: e.g. centipedes and millipedes
Myrmecobius fasciatus: small Australian marsupial having long snout and strong claws for feeding on termites; nearly extinct
Myrmecophaga jubata: large shaggy-haired toothless anteater with long tongue and powerful claws; of South America
myrmecophile: an organism such as an insect that habitually shares the nest of a species of ant
Mytilus edulis: a mussel with a dark shell that lives attached to rocks
Myxine glutinosa: typical hagfish
Myxinikela siroka: fossil hagfish of the Pennsylvanian period (c. 300 million years ago) that resembled modern hagfishes
Myxocephalus aenaeus: small sculpin of the coast of New England
myxoma virus: a poxvirus closely related to smallpox virus; causes benign gelatinous tumors in humans
myxosporidian: mostly parasitic in fishes and including various serious pathogens
myxovirus: any of a group of RNA viruses including those that cause influenza and mumps
Naemorhedus goral: small goat antelope with small conical horns; of southern Asian mountains
nail-tailed kangaroo: small wallabies with a horny nail on the tip of the tail
Naja nigricollis: aggressive cobra widely distributed in Africa; rarely bites but spits venom that may cause blindness
naked mole rat: fetal-looking colonial rodent of East Africa; neither mole nor rat; they feed on tubers and have a social structure similar to that of honeybees and termites
nanny: female goat
nanomia: small creatures resembling pieces of fuzzy rope; each with a cluster of swimming bells serving as the head and long elastic tentacles for drawing in prey
Nasalis larvatus: Borneo monkey having a long bulbous nose
Nasua narica: omnivorous mammal of Central America and South America
Natrix maura: a small harmless grass snake
Natrix natrix: harmless European snake with a bright yellow collar; common in England
Naucrates ductor: small pelagic fish often accompanying sharks or mantas
neb: a long projecting or anterior elongation of an animal's head; especially the nose
Necturus maculosus: aquatic North American salamander with red feathery external gills
needlefish: fish with long tubular snout and slim body covered with bony plates
Negaprion brevirostris: common shallow-water schooling shark of the Atlantic from North Carolina to Brazil and off west Africa; dangerous
Neisseria gonorrhoeae: the pus-producing bacterium that causes gonorrhea
nekton: the aggregate of actively swimming animals in a body of water ranging from microscopic organisms to whales
nematode: unsegmented worms with elongated rounded body pointed at both ends; mostly free-living but some are parasitic
nemertean: soft unsegmented marine worms that have a threadlike proboscis and the ability to stretch and contract
Neoceratodus forsteri: an endangered species of lungfish found in rivers in Queensland
Neophron percnopterus: small mostly white vulture of Africa and southern Eurasia
Neotoma cinerea: any of several bushy-tailed rodents of the genus Neotoma of western North America; hoards food and other objects
Neotoma floridana: large greyish-brown wood rat of the southeastern United States
Neotoma fuscipes: host to Lyme disease tick (Ixodes pacificus) in northern California
Nephrops norvegicus: edible European lobster resembling the American lobster but slenderer
nerita: a neritid gastropod having a short smooth or spirally ridged shell with thick usually toothed outer lip and toothed operculum
Nerita peloronta: gastropod having reddish toothlike projections around the shell opening; of the Caribbean area
neritid: operculate seasnail of coastal waters with a short spiral shell
neritina: ornately marked and brightly colored snails of brackish waters
Nerodia sipedon: in some classifications placed in the genus Nerodia; western United States snake that seldom ventures far from water
nervure: one of the horny ribs that stiffen and support the wing of an insect
nester: a bird that has built (or is building) a nest
Nestor notabilis: large brownish-green New Zealand parrot
neural tube: a tube of ectodermal tissue in the embryo from which the brain and spinal cord develop
neuropteran: insect having biting mouthparts and four large membranous wings with netlike veins
Neurotrichus gibbsii: greyish-black shrew mole of the United States and Canada
New World anteater: any of several tropical American mammals of the family Myrmecophagidae which lack teeth and feed on ants and termites
New World blackbird: any bird of the family Icteridae whose male is black or predominantly black
New World chat: birds having a chattering call
New World coral snake: any of several venomous New World snakes brilliantly banded in red and black and either yellow or white; widely distributed in South America and Central America
New World flycatcher: large American birds that characteristically catch insects on the wing
New World goldfinch: American finch whose male has yellow body plumage in summer
New World jay: a North American jay
New World least weasel: of Canada and northeastern United States
New World monkey: hairy-faced arboreal monkeys having widely separated nostrils and long usually prehensile tails
New World mouse: a variety of rodent
New World oriole: American songbird; male is black and orange or yellow
New World porcupine: arboreal porcupine
New World sparrow: sparrow-like North American finches
New World vulture: large birds of prey superficially similar to Old World vultures
New World warbler: small bright-colored American songbird with a weak unmusical song
New Zealand wren: birds of New Zealand that resemble wrens
Newfoundland dog: a breed of very large heavy dogs with a thick coarse usually black coat; highly intelligent dogs and vigorous swimmers; developed in Newfoundland
newt: small usually bright-colored semiaquatic salamanders of North America and Europe and northern Asia
night bird: any bird associated with night: owl; nightingale; nighthawk; etc
night heron: nocturnal or crepuscular herons
night lizard: small secretive nocturnal lizard of southwestern North America and Cuba; bear live young
night raven: any bird that cries at night
nit: egg or young of an insect parasitic on mammals especially a sucking louse; often attached to a hair or item of clothing
nitrate bacterium: any of the nitrobacteria that oxidize nitrites into nitrates
nitric bacteria: soil bacteria that convert nitrites to nitrates
nitrite bacterium: any of the nitrobacteria that oxidize ammonia into nitrites
nitrobacterium: any of the bacteria in the soil that take part in the nitrogen cycle; they oxidize ammonium compounds into nitrites or oxidize nitrites into nitrates
nitrosobacteria: soil bacteria that oxidize ammonia to nitrites
Noctiluca miliaris: large bioluminescent marine protozoan
noctuid: usually dull-colored medium-sized nocturnal moth; the usually smooth-bodied larvae are destructive agricultural pests
Nomia melanderi: a common solitary bee important for pollinating alfalfa in the western United States
nonpasserine bird: chiefly arboreal birds especially of the order Coraciiformes
nonstarter: a horse that fails to run in a race for which it has been entered
Norfolk terrier: English breed of small terrier with a straight wiry grizzled coat and dropped ears
northern snakehead: a voracious freshwater fish that is native to northeastern China; can use fin to walk and can survive out of water for three days; a threat to American populations of fish
Norwegian elkhound: breed of compact medium-sized dog with a heavy grey coat developed in Norway for hunting elk
Norwich terrier: English breed of small short-legged terrier with a straight wiry red or grey or black-and-tan coat and erect ears
nostoc: found in moist places as rounded jellylike colonies
Notechis scutatus: highly venomous brown-and-yellow snake of Australia and Tasmania
Notemigonus crysoleucas: shiner of eastern North America having golden glints; sometimes also called `bream'
nothosaur: extinct marine reptile with longer more slender limbs than plesiosaurs and less completely modified for swimming
notochord: a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates
Notonecta undulata: predaceous aquatic insect that swims on its back and may inflict painful bites
Notophthalmus viridescens: red terrestrial form of a common North American newt
Notornis mantelli: flightless New Zealand birds similar to gallinules
Notoryctus typhlops: small burrowing Australian marsupial that resembles a mole
Notropis atherinoides: small blunt-nosed fish of Great Lakes and Mississippi valley with a greenish luster
Notropis cornutus: the common North American shiner
Nucifraga caryocatactes: Old World nutcracker
Nucifraga columbiana: nutcracker of the western United States
nude mouse: a mouse with a genetic defect that prevents them from growing hair and also prevents them from immunologically rejecting human cells and tissues; widely used in preclinical trials
nudibranch: any of various marine gastropods of the suborder Nudibranchia having a shell-less and often beautifully colored body
Numenius arquata: common Eurasian curlew
Numenius borealis: New World curlew that breeds in northern North America
Numida meleagris: a west African bird having dark plumage mottled with white; native to Africa but raised for food in many parts of the world
nummulite: large fossil protozoan of the Tertiary period
nutcracker: speckled birds that feed on nuts
nutcracker: any of various small short-tailed songbirds with strong feet and a sharp beak that feed on small nuts and insects
Nyctanassa violacea: North American night heron
Nyctereutes procyonides: small wild dog of eastern Asia having facial markings like those of a raccoon
Nycticebus tardigradua: stocky lemur of southeastern Asia
Nycticorax nycticorax: night heron of both Old and New Worlds
nymph: a larva of an insect with incomplete metamorphosis (as the dragonfly or mayfly)
Nymphalis antiopa: of temperate regions; having dark purple wings with yellow borders
Nymphicus hollandicus: small grey Australian parrot with a yellow crested head
obligate anaerobe: an organism that cannot grow in the presence of oxygen
oceanic bird: bird of the open seas
Ochotona collaris: similar to little chief hare and may be same species
Ochotona princeps: North American pika
octopod: a cephalopod with eight arms but lacking an internal shell
Ocyurus chrysurus: superior food fish of the tropical Atlantic and Caribbean with broad yellow stripe along the sides and on the tail
odd-toed ungulate: placental mammals having hooves with an odd number of toes on each foot
Odobenus divergens: a walrus of the Bering Sea and northern Pacific
Odobenus rosmarus: a walrus of northern Atlantic and Arctic waters
Odocoileus hemionus: long-eared deer of western North America with two-pronged antlers
Odocoileus hemionus columbianus: mule deer of western Rocky Mountains
Odocoileus Virginianus: common North American deer; tail has a white underside
odonate: large primitive predatory aquatic insect having two pairs of membranous wings
Odontaspis taurus: shallow-water shark with sharp jagged teeth found on both sides of Atlantic; sometimes dangerous to swimmers
Oecanthus fultoni: pale yellowish tree cricket widely distributed in North America
Oedogoniales: simple or branched filamentous freshwater green algae
Oestrus ovis: larvae are parasitic on sheep
offspring: any immature animal
oil beetle: any of various beetles that exude an oily substance from the leg joints that deters enemies
Okapia johnstoni: similar to the giraffe but smaller with much shorter neck and stripe on the legs
Old English sheepdog: large sheepdog with a profuse shaggy bluish-grey-and-white coat and short tail; believed to trace back to the Roman occupation of Britain
Old World beaver: a European variety of beaver
Old World buffalo: any of several Old World animals resembling oxen including, e.g., water buffalo; Cape buffalo
Old World chat: songbirds having a chattering call
Old World coot: a coot found in Eurasia
Old World coral snake: any of various venomous elapid snakes of Asia and Africa and Australia
Old World crayfish: small crayfish of Europe and Asia and western North America
Old World flycatcher: any of a large group of small songbirds that feed on insects taken on the wing
Old World jay: a European jay
Old World least weasel: of Europe
Old World monkey: of Africa or Arabia or Asia; having nonprehensile tails and nostrils close together
Old World oriole: mostly tropical songbird; the male is usually bright orange and black
Old World porcupine: terrestrial porcupine
Old World quail: small game bird with a rounded body and small tail
Old World scops owl: European scops owl
Old World vulture: any of several large vultures of Africa and Eurasia
Old World warbler: small active brownish or greyish Old World birds
Old world white pelican: similar to American white pelican
oligochaete: hermaphroditic terrestrial and aquatic annelids having bristles borne singly along the length of the body
Omaha: thoroughbred that won the triple crown in 1935
omasum: the third compartment of the stomach of a ruminant
ommastrephes: extremely active cylindrical squid with short strong arms and large rhombic terminal fins
omnivore: an animal that feeds on both animal and vegetable substances
Omomyid group: extinct tiny nocturnal lower primates that fed on fruit and insects; abundant in North America and Europe 30 to 50 million years ago; probably gave rise to the tarsiers; some authorities consider them ancestral to anthropoids but others consider them only cousins
Oncorhynchus keta: a large Pacific salmon with small spots on its back; an important food fish
Oncorhynchus kisutch: small salmon of northern Pacific coasts and the Great Lakes
Oncorhynchus nerka: small salmon with red flesh; found in rivers and tributaries of the northern Pacific and valued as food; adults die after spawning
Oncorhynchus tshawytscha: large Pacific salmon valued as food; adults die after spawning
Ondatra zibethica: beaver-like aquatic rodent of North America with dark glossy brown fur
onion yellow-dwarf virus: the virus that produces stunting and yellowing of the leaves of onion plants
onychophoran: any of numerous velvety-skinned wormlike carnivorous animals common in tropical forests having characteristics of both arthropods and annelid worms
openbill: stork with a grooved bill whose upper and lower parts touch only at the base and tip
operculum: a hard flap serving as a cover for (a) the gill slits in fishes or (b) the opening of the shell in certain gastropods when the body is retracted
Opheodrys aestivus: of southern and eastern United States
Opheodrys vernalis: of western and central United States
ophidian: limbless scaly elongate reptile; some are venomous
Ophiodon elongatus: food fish of the northern Pacific related to greenlings
Ophiophagus hannah: large cobra of southeastern Asia and the East Indies; the largest venomous snake; sometimes placed in genus Naja
Opisthocomus hoazin: crested ill-smelling South American bird whose young have claws on the first and second digits of the wings
opossum rat: terrestrial marsupials of southern South America that resemble shrews
opossum shrimp: shrimp-like crustaceans whose females carry eggs and young in a pouch between the legs
opossum: small furry Australian arboreal marsupials having long usually prehensile tails
opossum: nocturnal arboreal marsupial having a naked prehensile tail found from southern North America to northern South America
Opsanus tau: bottom-dwelling fish having scaleless slimy skin and a broad thick head with a wide mouth
orb-weaving spider: a spider that spins a circular (or near circular) web
Orcinus orca: predatory black-and-white toothed whale with large dorsal fin; common in cold seas
Ord kangaroo rat: most widely distributed kangaroo rat: plains and mountain areas of central and western United States
order Acarina: mites and ticks
order Accipitriformes: in some classifications an alternative name for the Falconiformes
order Actiniaria: sea anemones
order Actinomycetales: filamentous or rod-shaped bacteria
order Actinomyxidia: parasites of worms
order Aepyorniformes: huge extinct flightless birds: elephant birds
order Alcyonaria: corals and sea anemones having eight branches
order Amoebida: the animal order including amoebas
order Amphipoda: small flat-bodied semiterrestrial crustaceans: whale lice; sand-hoppers; skeleton shrimp
order Anacanthini: at least partially equivalent to the order Gadiformes in some classifications
order Anaspida: extinct order of jawless vertebrates
order Anguilliformes: elongate fishes with pelvic fins and girdle absent or reduced
order Anoplura: sucking lice
order Anostraca: small aquatic crustaceans lacking a carapace: fairy shrimps; brine shrimps
order Anseriformes: ducks; geese; swans; screamers
order Apodiformes: swifts; hummingbirds
order Apterygiformes: a ratite bird order: flightless ground birds having vestigial wings and long bills and small eyes: kiwis
order Araneida: spiders
order Artiodactyla: an order of hooved mammals of the subclass Eutheria (including pigs and peccaries and hippopotami and members of the suborder Ruminantia) having an even number of functional toes
order Batrachia: frogs, toads, tree toads
order Belemnoidea: order of extinct dibranchiate cephalopods related to the surviving spirulas
order Berycomorphi: an order of spiny-finned fish in the superorder Acanthopterygii
order Branchiura: copepods with suctorial mouthparts; parasitic on fishes
order Caprimulgiformes: goatsuckers; frogmouths; oilbirds
order Carnivora: cats; lions; tigers; panthers; dogs; wolves; jackals; bears; raccoons; skunks; and members of the suborder Pinnipedia
order Casuariiformes: a ratite bird order: cassowaries and emus
order Cestida: ctenophore having short tentacles; one family
order Cetacea: an order of Eutheria
order Charadriiformes: large diverse order of aquatic birds found along seacoasts and inland waters: shorebirds and coastal diving birds; most feed on anima life
order Charales: small order of macroscopic fresh and brackish water algae with a distinct axis: stoneworts
order Chiroptera: an old order dating to early Eocene: bats: suborder Megachiroptera (fruit bats); suborder Microchiroptera (insectivorous bats)
order Chlorococcales: unicellular green algae that reproduce by spores
order Ciconiiformes: order of chiefly tropical marsh-dwelling fish-eating wading birds with long legs and bills and (except for flamingos) unwebbed feet: herons; storks; spoonbills; flamingos; ibises
order Cilioflagellata: in some classifications considered a phylum of the kingdom Protista; in others included in the plant phylum Pyrrophyta
order Coccidia: an order in the subclass Telosporidia
order Coleoptera: beetles
order Collembola: minute wingless arthropods: springtails
order Columbiformes: sand grouse; pigeons; doves; extinct dodos and solitaires
order Conodontophorida: extinct order of primitive vertebrates; the precise taxonomy is not clear; in some classifications considered a separate phylum
order Coraciiformes: rollers; kingfishers; hornbills; hoopoes; motmots; bee eaters; todies
order Corrodentia: an order of insects: includes booklice and bark-lice
order Crocodilia: crocodiles; alligators; caimans; gavials
order Cuculiformes: cuckoos; touracos; etc.
order Cyclostomata: primitive jawless aquatic vertebrate: lampreys; hagfishes
order Cydippidea: ctenophores having two long pinnate tentacles
order Cypriniformes: an order of animals including almost entirely freshwater fishes: characins; loaches; carp; suckers; sometimes classified as a suborder of Ostariophysi
order Decapoda: lobsters; crayfish; crabs; shrimps; prawns
order Decapoda: squids and cuttlefishes
order Dermaptera: earwigs and a few related forms
order Dermoptera: flying lemurs
order Dictyoptera: in some classifications replaced by the orders (here suborders) Blattodea (cockroaches) and Manteodea (mantids); in former classifications often subsumed under a much broader order Orthoptera
order Dinocerata: small order of primitive ungulates of the Paleocene and Eocene
order Dinornithiformes: a ratite bird order: recently extinct flightless birds of New Zealand
order Diptera: a large order of insects having a single pair of wings and sucking or piercing mouths; includes true flies and mosquitoes and gnats and crane flies
order Discocephali: small order of fishes comprising the remoras
order Edentata: order of mammals having few or no teeth including: New World anteaters; sloths; armadillos
order Embioptera: web spinners
order Ephemeroptera: mayflies
order Eubacteriales: one of two usually recognized orders of true bacteria; Gram-positive spherical or rod-shaped forms; some are motile; in some classifications considered an order of Schizomycetes
order Euphausiacea: small commonly luminescent crustaceans; important element of marine plankton: krill
order Eurypterida: extinct aquatic arthropods of the Paleozoic
order Exocycloida: flat sea urchins
order Falconiformes: chiefly diurnal carnivorous birds having hooked beaks and long talons with opposable hind toe: falcons; hawks; eagles; ospreys; caracaras; vultures
order Foraminifera: foraminifers
order Fucales: coextensive with the family Fucaceae
order Gadiformes: cods, haddocks, grenadiers; in some classifications considered equivalent to the order Anacanthini
order Galliformes: pheasants; turkeys; grouse; partridges; quails; chickens; brush turkeys; curassows; hoatzins
order Ganoidei: a group of mostly extinct primitive bony fishes characterized by armor-like bony scales
order Gaviiformes: large aquatic birds: loons and some extinct forms
order Geophilomorpha: small elongate centipedes living in soil and under stones and having more than 30 pairs of legs
order Gregarinida: an order in the subclass Telosporidia
order Gruiformes: inland marsh-dwelling birds with long legs and necks and bills that wade in water in search of food: cranes; rails; bustards
order Gymnophiona: an order of amphibians including caecilians
order Haemosporidia: an order in the subclass Telosporidia
order Haplosporidia: an order in the subclass Acnidosporidia
order Heliozoa: mostly freshwater protozoa
order Hemiptera: plant bugs; bedbugs; some true bugs; also includes suborders Heteroptera (true bugs) and Homoptera (e.g., aphids, plant lice and cicadas)
order Heterotrichales: yellow-green algae with simple or branching filaments; comprising the single family Tribonemaceae
order Hymenoptera: an order of insects including: bees; wasps; ants; ichneumons; sawflies; gall wasps; etc.
order Hypermastigina: cellulose-producing flagellates
order Hyracoidea: hyraxes and some extinct animals
order Ichthyosauria: extinct marine reptiles: ichthyosaurs
order Ictodosauria: extinct reptiles of the later Triassic period
order Insectivora: shrews; moles; hedgehogs; tenrecs
order Insessores: a bird with feet adapted for perching (as on tree branches); this order is now generally abandoned by taxonomists
order Isopoda: woodlice
order Isoptera: order of social insects that live in colonies, including: termites; often placed in subclass Exopterygota
order Isospondyli: most primitive teleost fishes; all are soft-finned: salmon; trout; herring; shad; sardines; anchovies; whitefish; smelts; tarpon
order Lagomorpha: rabbits; hares; pikas; formerly considered the suborder Duplicidentata of the order Rodentia
order Laminariales: in some classifications coextensive with family Laminariaceae: marine brown algae of cold or polar seas
order Lepidoptera: moths and butterflies
order Lobata: ctenophore having tentacles only in the immature stage; body compressed vertically having two large oral lobes and four pointed processes
order Loricata: former name for the order Crocodylia
order Madreporaria: stony corals
order Mallophaga: biting lice
order Marsupialia: coextensive with the subclass Metatheria
order Mecoptera: an order of carnivorous insects usually having long membranous wings and long beaklike heads with chewing mouths at the tip
order Monotremata: coextensive with the subclass Prototheria
order Myaceae: clams
order Mycoplasmatales: coextensive with the family Mycoplasmataceae
order Mycrosporidia: an order in the subclass Cnidosporidia
order Mysidacea: opossum shrimp
order Myxobacteriales: an order of higher bacteria
order Myxosporidia: an order in the subclass Cnidosporidia
order Neuroptera: an order of insects including: lacewings; antlions; dobsonflies; alderflies; fish flies; mantispids; spongeflies
order Notostraca: small freshwater crustaceans with a shield-shaped carapace
order Nudibranchia: comprising numerous marine gastropod mollusks lacking a shell in the adult state and usually having a body like a slug
order Octopoda: octopuses and paper nautilus
order Odonata: dragonflies and damselflies
order Ornithischia: extinct terrestrial reptiles having bird-like pelvises: armored dinosaurs (thyreophorans); boneheaded and horned dinosaurs (marginocephalians); duck-billed dinosaurs (euronithopods)
order Orthoptera: grasshoppers and locusts; crickets
order Ostariophysi: in some classifications considered a superorder comprising the Cypriniformes and the Siluriformes
Order Osteoglossiformes: teleost fish with bony tongues
order Ostracodermi: extinct group of armored jawless vertebrates; taxonomy is not clear
order Passeriformes: largest order of birds comprising about half the known species; rooks; finches; sparrows; tits; warblers; robins; wrens; swallows; etc.; the four suborders are Eurylaimi and Tyranni and Menurae and Oscines or Passeres
order Pectinibranchia: large order of gastropods comprising univalve mollusks that have a single gill resembling a comb
order Pediculati: anglers and batfishes; spiny-finned marine fishes having pectoral fins at the ends of armlike processes and a long movable spine on the dorsal fin to lure prey to the large mouth
order Pedipalpi: whip scorpions
order Pelecaniformes: pelicans; frigate birds; gannets; cormorants
order Pelycosauria: edaphosaurus; dimetrodon
order Percomorphi: one of the largest natural groups of fishes of both marine and fresh water: true perches; basses; tuna
order Perissodactyla: nonruminant ungulates: horses; tapirs; rhinoceros; extinct forms
order Phalangida: harvestmen
order Phasmatodea: in some classifications considered a suborder of Orthoptera: stick insects; leaf insects
order Pholidota: pangolins; in some former classifications included in the order Edentata
order Picariae: term used in some classifications as nearly equivalent to the order Coraciiformes
order Piciformes: woodpeckers; jacamars; puffbirds; barbets; honey guides; toucans
order Platyctenea: an order of Tentaculata
order Plecoptera: stoneflies
order Pleuronectiformes: flatfishes: halibut; sole; flounder; plaice; turbot; tonguefishes
order Podicipediformes: grebes
order Polymastigina: small usually parasitic flagellates
order Primates: an animal order including lemurs and tarsiers and monkeys and apes and human beings
order Proboscidea: an order of animals including elephants and mammoths
order Procellariiformes: petrels; albatrosses; shearwaters; diving petrels
order Protura: minute wingless arthropods: telsontails
order Pseudomonadales: one of two usually recognized orders of true bacteria; Gram-negative spiral or spherical or rod-shaped bacteria usually motile by polar flagella; some contain photosynthetic pigments
order Pseudoscorpionida: false scorpions
order Psittaciformes: an order of birds including parrots and amazons and cockatoos and lorikeets and lories and macaws and parakeets
order Pterosauria: extinct flying reptiles: pterosaurs
order Pulmonata: large order of gastropods usually breathing by means of a lung-like sac comprising most land snails and slugs and many freshwater snails
order Pycnogonida: sea spiders
order Radiolaria: marine protozoa
order Rajiformes: fish with dorsoventrally flattened bodies; includes: rays; skates; guitarfishes; sawfishes
order Raptores: term used in former classifications; erroneously grouped together birds of the orders Falconiformes and Strigiformes
order Rheiformes: a ratite bird order: birds intermediate in characteristics between ostriches and emus: recent and extinct rheas
order Rhynchocephalia: tuataras; extinct forms from middle Triassic
order Rickettsiales: pleomorphic Gram-negative microorganisms
order Rodentia: small gnawing animals: porcupines; rats; mice; squirrels; marmots; beavers; gophers; voles; hamsters; guinea pigs; agoutis
order Sarcosporidia: imperfectly known parasites of the muscles of vertebrates
order Saurischia: extinct terrestrial reptiles: theropods (carnivorous); sauropods (herbivorous)
order Sauropterygia: extinct marine reptiles: plesiosaurs; nothosaurs
order Scandentia: a small order comprising only the tree shrews: in some classifications tree shrews are considered either primates (and included in the suborder Prosimii) or true insectivores (and included in the order Insectivora)
order Scleroparei: scorpionfishes; sculpins; gurnards; greenlings; flying gurnards
order Scorpionida: true scorpions
order Siluriformes: an order of fish belonging to the superorder Malacopterygii including catfishes
order Siphonaptera: fleas
order Siphonophora: marine colonial hydrozoans
order Sirenia: an animal order including: manatees; dugongs; Steller's sea cow
order Solenichthyes: bellows fishes; shrimpfishes; cornetfishes; pipefishes; small order of chiefly tropical marine fishes of varied and bizarre form all having a small mouth at the end of a drawn-out tubular snout
order Solenogastres: an order of Amphineura
order Spatangoida: heart-shaped sea urchins
order Sphenisciformes: penguins
order Spirochaetales: higher bacteria; slender spiral rodlike forms
order Squamata: diapsid reptiles: snakes and lizards
order Stegocephalia: in former classifications a division of class Amphibia comprising all pre-Jurassic and some later extinct large salamandriform amphibia
order Stereospondyli: formerly a suborder of Stegocephalia; amphibia having vertebrae whose component elements are fused into a single piece
order Stomatopoda: mantis shrimps
order Strigiformes: owls
order Struthioniformes: a ratite bird order: ostriches and related extinct birds; known from the Pleistocene onward
order Synentognathi: order of fishes having spineless fins; needlefishes; sauries; flying fishes; halfbeaks
order Temnospondyli: formerly a suborder of Stegocephalia; large Carboniferous and Permian amphibians having vertebrae in which some elements remain separate
order Testacea: testacean rhizopods
order Testudinata: tortoises and turtles
order Tetraodontiformes: boxfishes; filefishes; globefishes; ocean sunfishes; triggerfishes; puffers
order Thecodontia: extinct terrestrial reptiles having teeth set in sockets; of the late Permian to Triassic
order Therapsida: extinct mammal-like reptiles found inhabiting all continents from the mid Permian to late Triassic
order Thysanoptera: thrips
order Thysanura: firebrats; silverfish; machilids
order Tinamiformes: coextensive with the family Tinamidae
order Torpediniformes: rays with bodies shaped like torpedoes
order Trichoptera: an order of insects consisting of caddis flies
order Trogoniformes: trogons
order Tubulidentata: an order of Eutheria
order Ulvales: an order of protoctist
order Urodella: salamanders; newts; congo snakes
order Volvocales: chiefly freshwater green algae; solitary or colonial
order Xiphosura: horseshoe crabs and extinct forms
order Zeomorphi: dories
order Zygnematales: pond scums; desmids
Orectolobus barbatus: shark of the western Pacific with flattened body and mottled skin
Oreortyx picta palmeri: California partridge; slightly larger than the California quail
Oriental scops owl: Asian scops owl
Oriolus oriolus: bright yellow songbird with black wings
ornithischian: herbivorous dinosaur with a pelvis like that of a bird
ornithomimid: lightly built medium-sized dinosaur having extremely long limbs and necks with small heads and big brains and large eyes
ornithopod: bipedal herbivorous dinosaur
Ornithorhynchus anatinus: small densely furred aquatic monotreme of Australia and Tasmania having a broad bill and tail and webbed feet; only species in the family Ornithorhynchidae
orphan: a young animal without a mother
Orpington: English breed of large chickens with white skin
orthomyxovirus: a group of viruses including those causing influenza
Orthopristis chrysopterus: found from Long Island southward
orthopteran: any of various insects having leathery forewings and membranous hind wings and chewing mouthparts
Orthotomus sutorius: tropical Asian warbler that stitches leaves together to form and conceal its nest
Ortilis vetula macalli: of Mexico and Texas
ortygan: any of several East Indian birds
Orycteropus afer: nocturnal burrowing mammal of the grasslands of Africa that feeds on termites; sole extant representative of the order Tubulidentata
Oryctolagus cuniculus: common greyish-brown burrowing animal native to southern Europe and northern Africa but introduced elsewhere; widely domesticated and developed in various colors and for various needs; young are born naked and helpless
Oryx gazella: large South African oryx with a broad black band along its flanks
oryx: large African antelope with long straight nearly upright horns
Oryzomys palustris: hardy agile rat of grassy marshes of Mexico and the southeastern United States
oscine: passerine bird having specialized vocal apparatus
Osmerus eperlanus: the common smelt of Europe
Osmerus mordax: important marine and landlocked food fish of eastern North America and Alaska
ostracoderm: extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic
Otis tarda: largest European land bird
otter: freshwater carnivorous mammal having webbed and clawed feet and dark brown fur
otter hound: hardy British hound having long pendulous ears and a thick coarse shaggy coat with an oily undercoat; bred for hunting otters
Otus asio: small North American owl having hornlike tufts of feathers whose call sounds like a quavering whistle
Ovalipes ocellatus: brightly spotted crab of sandy beaches of the Atlantic coast of the United States
ovenbird: small brownish South American birds that build oven-shaped clay nests
Ovibos moschatus: large shaggy-coated bovid mammal of Canada and Greenland; intermediate in size and anatomy between an ox and a sheep
ovipositor: egg-laying tubular structure at the end of the abdomen in many female insects and some fishes
oviraptorid: advanced carnivorous theropod
Ovis ammon: wild sheep of semidesert regions in central Asia
Ovis aries: any of various breeds raised for wool or edible meat or skin
Ovis montana dalli: large white wild sheep of northwestern Canada and Alaska
Ovis musimon: wild mountain sheep of Corsica and Sardinia
Ovis vignei: bearded reddish sheep of southern Asia
owlet: young owl
ox: an adult castrated bull of the genus Bos; especially Bos taurus
ox: any of various wild bovines especially of the genera Bos or closely related Bibos
oxtail: the skinned tail of cattle; used especially for soups
Oxylebius pictus: greenling with whitish body marked with black bands
Oxyura jamaicensis: reddish-brown stiff-tailed duck of North America and northern South America
Oxyuranus scutellatus: large highly venomous snake of northeastern Australia
oyster: marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters
oyster catcher: black-and-white shorebird with stout legs and bill; feed on oysters etc.
oyster fish: a variety of toadfish
oyster shell: a shell of an oyster
pacemaker: a horse used to set the pace in racing
pacer: a horse trained to a special gait in which both feet on one side leave the ground together
pachycephalosaur: bipedal herbivore having 10 inches of bone atop its head; largest boneheaded dinosaur ever found
pachyderm: any of various nonruminant hoofed mammals having very thick skin: elephant; rhinoceros; hippopotamus
Pacific bottlenose dolphin: a bottlenose dolphin found in the Pacific Ocean
Pacific giant salamander: large (to 7 inches) salamander of western North America
Pacific newt: any of several rough-skinned newts found in western North America
Pacific spiny dogfish: dogfish of Pacific coast of North America
Pacific tree toad: the most commonly heard frog on the Pacific coast of America
Pacific tripletail: tripletail found in the Pacific
pack animal: an animal (such as a mule or burro or horse) used to carry loads
packhorse: a workhorse used as a pack animal
pad: the fleshy cushion-like underside of an animal's foot or of a human's finger
Padda oryzivora: small finch-like Indonesian weaverbird that frequents rice fields
paddymelon: small reddish-brown wallabies of scrubby areas of Australia and New Guinea
Pagellus centrodontus: food fish of European coastal waters
Pagophila eburnea: white Arctic gull; migrates as far south as England and New Brunswick
Pagophilus groenlandicus: common Arctic seal; the young are all white
Pagrus pagrus: food fish of the Mediterranean and Atlantic coasts of Europe and America
Palaemon australis: large (a foot or more) edible freshwater prawn common in Australian rivers
pale chrysanthemum aphid: important pest of chrysanthemums
Paleacrita vernata: moth whose larvae are spring cankerworms
palfrey: especially a light saddle horse for a woman
Pallas's cat: small wildcat of the mountains of Siberia and Tibet and Mongolia
palm cat: spotted or striped arboreal civet of southeast Asia and East Indies
Palometa simillima: smaller than Florida pompano; common in West Indies
palomino: a horse of light tan or golden color with cream-colored or white mane and tail
Pan paniscus: small chimpanzee of swamp forests in Zaire; a threatened species
Pan troglodytes: intelligent somewhat arboreal ape of equatorial African forests
Pan troglodytes schweinfurthii: long-haired chimpanzees of east-central Africa; closely related to the central chimpanzees
Pan troglodytes troglodytes: black-faced chimpanzees of central Africa; closely related to eastern chimpanzees
Pan troglodytes verus: masked or pale-faced chimpanzees of western Africa; distantly related to the eastern and central chimpanzees; possibly a distinct species
pancake turtle: voracious aquatic turtle with a flat flexible shell covered by a leathery skin; can inflict painful bites
Pandion haliaetus: large harmless hawk found worldwide that feeds on fish and builds a bulky nest often occupied for years
Panonychus ulmi: small web-spinning mite; a serious orchard pest
panther: a leopard in the black color phase
Panthera leo: large gregarious predatory feline of Africa and India having a tawny coat with a shaggy mane in the male
Panthera onca: a large spotted feline of tropical America similar to the leopard; in some classifications considered a member of the genus Felis
Panthera pardus: large feline of African and Asian forests usually having a tawny coat with black spots
Panthera tigris: large feline of forests in most of Asia having a tawny coat with black stripes; endangered
Panthera uncia: large feline of upland central Asia having long thick whitish fur
paper wasp: any of several social wasps that construct nests of a substance like paper
papillon: small slender toy spaniel with erect ears and a black-spotted brown to white coat
Papio ursinus: greyish baboon of southern and eastern Africa
papovavirus: any of a group of animal viruses associated with or causing papillomas or polyomas
Paprilus alepidotus: butterfish up to a foot long of Atlantic waters from Chesapeake Bay to Argentina
Paracheirodon axelrodi: small bright red and blue aquarium fish from streams in Brazil and Colombia
parainfluenza virus: a virus that causes upper respiratory infection (including the common cold and bronchiolitis); most often in children
parakeet: any of numerous small slender long-tailed parrots
Paralichthys dentatus: flounder of eastern coast of North America
Paralichthys lethostigmus: flounder of southern United States
Paralithodes camtschatica: large edible crab of northern Pacific waters especially along the coasts of Alaska and Japan
paramecia: any member of the genus Paramecium
paramyxovirus: a group of viruses including those causing mumps and measles
Paranthias furcifer: deep-sea fish of tropical Atlantic
parapodium: one of a pair of fleshy appendages of a polychete annelid that functions in locomotion and breathing
Parascalops breweri: mole of eastern North America
parasite: an animal or plant that lives in or on a host (another animal or plant); it obtains nourishment from the host without benefiting or killing the host
parazoan: primitive multicellular marine animal whose porous body is supported by a fibrous skeletal framework; usually occurs in sessile colonies
pariah dog: ownerless half-wild mongrel dog common around Asian villages especially India
Parophrys vitulus: popular pale brown food flatfish of the Pacific coast of North America
parr: the young of various fishes
parr: a young salmon up to 2 years old
parrot: usually brightly colored zygodactyl tropical birds with short hooked beaks and the ability to mimic sounds
parrotfish: gaudy tropical fishes with parrotlike beaks formed by fusion of teeth
partridge: small Old World gallinaceous game birds
partridge: heavy-bodied small-winged South American game bird resembling a gallinaceous bird but related to the ratite birds
Parula americana: small grey-blue wood warbler with yellow throat and breast; of eastern North America
Parus atricapillus: chickadee having a dark crown
Parus bicolor: crested titmouse of eastern and midwestern United States
Parus caeruleus: widely distributed European titmouse with bright cobalt blue wings and tail and crown of the head
Parus carolinensis: southern United States chickadee similar to the blackcap but smaller
parvo: any of a group of viruses containing DNA in an icosahedral protein shell and causing disease in dogs and cattle; not known to be associated with any human disease
Passer domesticus: small hardy brown-and-grey bird native to Europe
Passer montanus: Eurasian sparrow smaller than the house sparrow
passeriform bird: perching birds mostly small and living near the ground with feet having 4 toes arranged to allow for gripping the perch; most are songbirds; hatchlings are helpless
Passerina cyanea: small deep blue North American bunting
Pastor sturnus: glossy black bird with pink back and abdomen; chiefly Asian
Patella vulgata: marine limpet
pathogen: any disease-producing agent (especially a virus or bacterium or other microorganism)
Pavo cristatus: peafowl of India and Ceylon
Pavo muticus: peafowl of southeast Asia
paw: a clawed foot of an animal especially a quadruped
pea crab: tiny soft-bodied crab living commensally in the mantles of certain bivalve mollusks
peachick: a young peafowl
peacock: male peafowl; having a crested head and very large fanlike tail marked with iridescent eyes or spots
peahen: female peafowl
peanut worm: small unsegmented marine worm that when disturbed retracts its anterior portion into the body giving the appearance of a peanut
pearlfish: found living within the alimentary canals of e.g. sea cucumbers or between the shells of pearl oysters in or near shallow seagrass beds
pearly-shelled mussel: the pearly lining of the dark shells is a source of mother-of-pearl
pecker: bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects
Pecten irradians: a small scallop inhabiting shallow waters and mud flats of the Atlantic coast of North America
Pecten magellanicus: a large scallop inhabiting deep waters of the Atlantic coast of North America
pectoral fin: either of a pair of fins situated just behind the head in fishes that help control the direction of movement
Pediculus capitis: infests the head and body of humans
Pediculus corporis: a parasitic louse that infests the body of human beings
Pediculus humanus: head or body louse
Pedioecetes phasianellus: large grouse of prairies and open forests of western North America
Pedionomus torquatus: small Australian bird related to the button quail; classified as wading bird but inhabits plains
peeper: an animal that makes short high-pitched sounds
Peking man: fossils found near Beijing, China; they were lost during World War II
Pekingese: a Chinese breed of small short-legged dogs with a long silky coat and broad flat muzzle
pelecaniform seabird: large fish-eating seabird with four-toed webbed feet
Pelecanus erythrorhynchos: large American pelican; white with black wing feathers
pelican: large long-winged warm-water seabird having a large bill with a distensible pouch for fish
pellicle: thin protective membrane in some protozoa
pelvic fin: either of a pair of fins attached to the pelvic girdle in fishes that help control the direction of movement; correspond to hind limbs of a land vertebrate
pelycosaur: large primitive reptile having a tall spinal sail; of the Permian or late Paleozoic in Europe and North America
Pembroke Welsh corgi: the smaller and straight-legged variety of corgi having pointed ears and a short tail
pen: female swan
penguin: short-legged flightless birds of cold southern especially Antarctic regions having webbed feet and wings modified as flippers
penicillin-resistant bacteria: bacteria that are unaffected by penicillin
pennon: wing of a bird
pentail: brown tree shrew having a naked tail bilaterally fringed with long stiff hairs on the distal third; of Malaysia
pentastomid: wormlike arthropod having two pairs of hooks at the sides of the mouth; parasitic in nasal sinuses of mammals
Perca flavescens: North American perch
Perca fluviatilis: a perch native to Europe
perch: spiny-finned freshwater food and game fishes
perch: any of numerous spiny-finned fishes of various families of the order Perciformes
Percheron: one of a breed of grey or black draft horses originally used in France to draw heavy coaches or artillery
Percina tanasi: a small snail-eating perch of the Tennessee River
percoid: any of numerous spiny-finned fishes of the order Perciformes
peridinian: flagellate with a thick test composed of plates
Periplaneta americana: large reddish brown free-flying cockroach originally from southern United States but now widely distributed
Periplaneta australasiae: widely distributed in warm countries
Perisoreus canadensis: a jay of northern North America with black-capped head and no crest; noted for boldness in thievery
Perisoreus canadensis capitalis: a Canada jay with a white head; widely distributed from Montana to Arizona
Peristedion miniatum: sea robins having bony scutes on the body and barbels on the chin; found mostly on the continental slope
peristome: region around the mouth in various invertebrates
periwinkle: edible marine gastropod
Pernis apivorus: Old World hawk that feeds on bee larvae and small rodents and reptiles
Perodicticus potto: a kind of lemur
Perognathus flavescens: small rodent of open areas of United States plains states
Perognathus flavus: small pale yellowish soft-furred rodent of southwestern United States and Mexico
Perognathus hispidus: large stiff-haired rodent of shortgrass prairies of United States
Peromyscus eremicus: burrowing mouse of desert areas of southwestern United States
Peromyscus gossypinus: large dark mouse of southeastern United States
Peromyscus leucopus: American woodland mouse with white feet and underparts
Peromyscus maniculatus: brownish New World mouse; most widely distributed member of the genus
Persian cat: a long-haired breed of cat
Persian lamb: a karakul lamb
pest: any unwanted and destructive insect or other animal that attacks food or crops or livestock etc.
pet: a domesticated animal kept for companionship or amusement
Petaurista petaurista: East Indian flying squirrel
petrel: relatively small long-winged tube-nosed bird that flies far from land
Petromyzon marinus: large anadromous lamprey sometimes used as food; destructive of native fish fauna in the Great Lakes
Pezophaps solitaria: extinct flightless bird related to the dodo
Phalacrocorax carbo: large voracious dark-colored long-necked seabird with a distensible pouch for holding fish; used in Asia to catch fish
Phalaenoptilus nuttallii: goatsucker of western North America
Phalangium opilio: spiderlike arachnid with a small rounded body and very long thin legs
phalarope: small sandpiper-like shorebird having lobate toes and being good swimmers; breed in the Arctic and winter in the tropics
Phalaropus fulicarius: phalarope of northern oceans and lakes
Pharomacrus mocino: very rare Central American bird; the national bird of Guatemala
Phascolarctos cinereus: sluggish tailless Australian arboreal marsupial with grey furry ears and coat; feeds on eucalyptus leaves and bark
phasianid: a kind of game bird in the family Phasianidae
Phasianus colchicus: common pheasant having bright plumage and a white neck ring
phasmid: large cylindrical or flattened mostly tropical insects with long strong legs that feed on plants; walking sticks and leaf insects
pheasant: large long-tailed gallinaceous bird native to the Old World but introduced elsewhere
phenacomys: any of several vole-like terrestrial or arboreal rodents of cold forested regions of Canada and western United States
Philaenus spumarius: North American insect that severely damages grasses
Philomachus pugnax: common Eurasian sandpiper; the male has an erectile neck ruff in breeding season
Phlebotomus papatasii: any of various small dipterous flies; bloodsucking females can transmit sandfly fever and leishmaniasis
Phoca vitulina: small spotted seal of coastal waters of the northern hemisphere
Phocoena phocoena: the common porpoise of the northern Atlantic and Pacific
Phocoena sinus: a short porpoise that lives in the Gulf of California; an endangered species
Pholis gunnellus: slippery scaleless food fish of the northern Atlantic coastal waters
phoronid: hermaphrodite wormlike animal living in mud of the sea bottom
Photoblepharon palpebratus: fish of deep dark waters having a light organ below each eye
phototrophic bacteria: green and purple bacteria; energy for growth is derived from sunlight; carbon is derived from carbon dioxide or organic carbon
Phoxinus phoxinus: very small European freshwater fish common in gravelly streams
phragmacone: the thin conical chambered internal shell (either straight or curved) of a belemnite
Phthirius pubis: a louse that infests the pubic region of the human body
Phthorimaea operculella: greyish-brown moth whose larva is the potato tuberworm
Phthorimaea operculella: larva of potato moth; mines in leaves and stems of e.g. potatoes and tobacco
phycobilin: water-soluble proteinaceous pigments found in red algae and cyanobacteria
phycocyanin: blue pigment in algae
phycoerythrin: red pigment in red algae
Phylloscopus sibilatrix: European woodland warbler with dull yellow plumage
Phyllostomus hastatus: a variety of leaf-nosed bat
Phylloxera vitifoleae: destructive to various grape plants
phylum Acanthocephala: phylum or class of elongated wormlike parasites that live in the intestines of vertebrates: spiny-headed worms
phylum Annelida: segmented worms: earthworms; lugworms; leeches
phylum Arthropoda: jointed-foot invertebrates: arachnids; crustaceans; insects; millipedes; centipedes
phylum Aschelminthes: unsegmented worms: roundworms; threadworms; eelworms
phylum Brachiopoda: marine invertebrates that resemble mollusks
phylum Bryozoa: marine or freshwater animals that form colonies of zooids
phylum Chaetognatha: arrowworms: a group of small active transparent marine worms
phylum Chordata: comprises true vertebrates and animals having a notochord
phylum Coelenterata: hydras; polyps; jellyfishes; sea anemones; corals
phylum Cryptophyta: a phylum in the kingdom Protoctista
phylum Ctenophora: comb jellies; sea acorns; a small phylum formerly considered a class of Coelenterata
phylum Cycliophora: tiny marine organisms each the size of a period found in great numbers on lobsters' lips; identified tentatively in 1995 as a new phylum or as possible link between Entoprocta and Ectoprocta
phylum Echinodermata: radially symmetrical marine invertebrates including e.g. starfish and sea urchins and sea cucumbers
phylum Ectoprocta: coextensive with or a subphylum of Bryozoa
phylum Entoprocta: sometimes considered a subphylum of Bryozoa
phylum Mollusca: gastropods; bivalves; cephalopods; chitons
phylum Nemertina: proboscis worms
phylum Phoronida: small phylum of wormlike marine animals
phylum Platyhelminthes: flatworms
phylum Pogonophora: beard worms
phylum Porifera: coextensive with the subkingdom Parazoa: sponges
phylum Protozoa: in some classifications considered a superphylum or a subkingdom; comprises flagellates; ciliates; sporozoans; amoebas; foraminifers
phylum Pyrrophyta: a division of lower plants comprising unicellular and biflagellate algae that form starchy compounds
phylum Rotifera: a phylum including: rotifers
phylum Sipuncula: peanut worms
physa: any member of the genus Physa
Physeter catodon: large whale with a large cavity in the head containing spermaceti and oil; also a source of ambergris
phytoplankton: photosynthetic or plant constituent of plankton; mainly unicellular algae
Pica pica hudsonia: a magpie of Rocky Mountains in North America
piciform bird: any of numerous nonpasserine insectivorous climbing birds usually having strong bills for boring wood
pickerel: any of several North American species of small pike
picornavirus: a group of single-strand RNA viruses with a protein coat
piculet: small woodpeckers of South America and Africa and East Indies having soft rounded tail feathers
Picus viridis: woodpecker of Europe and western Asia
piddock: marine bivalve that bores into rock or clay or wood by means of saw-like shells
pied lemming: North American lemming having a white winter coat and some claws much enlarged
pierid: any of numerous pale-colored butterflies having three pairs of well-developed legs
Pieris brassicae: Old World form of cabbage butterfly
Pieris protodice: common North American form of cabbage butterfly
Pieris rapae: small widely distributed form
Pieris rapae: toxic green larva of a cabbage butterfly
pigeon: wild and domesticated birds having a heavy body and short legs
piggy: a young pig
pike: any of several elongate long-snouted freshwater game and food fishes widely distributed in cooler parts of the northern hemisphere
pike perch: any of several pike-like fishes of the perch family
pikeblenny: tropical American fishes; males are aggressively defensive of their territory
pill bug: small terrestrial isopod with a convex segmented body that can roll up into a ball
pilus: hairlike structure especially on the surface of a cell or microorganism
Pinctada margaritifera: tropical marine bivalve found chiefly off eastern Asia and Pacific coast of North America and Central America; a major source of pearls
pine sawyer: large beetle whose larvae bore holes in pine trees
pine snake: any of several bull snakes of eastern and southeastern United States found chiefly in pine woods; now threatened
pine spittlebug: North American insect that attacks pines
Pineus pinifoliae: a variety of adelgid
Pinguinus impennis: large flightless auk of rocky islands off northern Atlantic coasts; extinct
Pinicola enucleator: large grosbeak of coniferous forests of Old and New Worlds
pinnatiped: aquatic carnivorous mammal having a streamlined body specialized for swimming with limbs modified as flippers
Pinnotheres ostreum: tiny soft-bodied crab living within the mantle cavity of oysters
pinscher: any of three breeds of dogs whose ears and tail are usually cropped
pinto: a spotted or calico horse or pony
Pipa americana: a South American toad; incubates its young in pits in the skin of its back
Pipilo erythrophthalmus: common towhee of eastern North America
piping guan: a kind of guan
Pipistrellus pipistrellus: small European brown bat
Pipistrellus subflavus: one of the smallest bats of eastern North America
Piranga flava hepatica: common tanager of southwestern United States and Mexico
Piranga ludoviciana: of western North America; male is black and yellow and orange-red
Piranga olivacea: the male is bright red with black wings and tail
Piranga rubra: of middle and southern United States; male is deep rose-red the female mostly yellow
piroplasm: minute parasite of red blood cells of mammals transmitted by a tick and causing diseases of domestic animals
pisanosaur: primitive dinosaur found in Argentina
Pisces: a group of vertebrates comprising both cartilaginous and bony fishes and sometimes including the jawless vertebrates; not used technically
pistol shrimp: small shrimp that makes a snapping noise with one of their enlarged chelae
pit viper: New World vipers with hollow fangs and a heat-sensitive pit on each side of the head
Pithecanthropus erectus: former genus of primitive apelike men now Homo erectus
pitta: any bird of the genus Pitta; brilliantly colored chiefly terrestrial birds with short wings and tail and stout bills
Pituophis melanoleucus: bull snake of western North America that invades rodent burrows
Pitymys pinetorum: short-tailed glossy-furred burrowing vole of the eastern United States
placoderm: fish-like vertebrate with bony plates on head and upper body; dominant in seas and rivers during the Devonian; considered the earliest vertebrate with jaws
Placuna placenta: marine bivalve common in Philippine coastal waters characterized by a large thin flat translucent shell
planaria: free-swimming mostly freshwater flatworms; popular in laboratory studies for the ability to regenerate lost parts
plankton: the aggregate of small plant and animal organisms that float or drift in great numbers in fresh or salt water
planktonic algae: unicellular algae
Planococcus citri: feeds on a wide variety of cultivated plants but especially destructive to citrus
plant hopper: related to the leafhoppers and spittlebugs but rarely damages cultivated plants
plant virus: a plant pathogen that is a virus consisting of a single strand of RNA
Plantation walking horse: a horse marked by stamina and trained to move at a fast running walk
plantigrade: an animal that walks with the entire sole of the foot touching the ground as e.g. bears and human beings
plantlike flagellate: unicellular organisms having many characteristics of typical algae
planula: the flat ciliated free-swimming larva of hydrozoan coelenterates
plasmodium: multinucleate sheet of cytoplasm characteristic of some stages of such organisms as slime molds
Plasmodium vivax: parasitic protozoan of the genus Plasmodium that causes malaria in humans
plastron: (zoology) the part of a turtle's shell forming its underside
Platalea leucorodia: pure white crested spoonbill of southern Eurasia and northeastern Africa
Platichthys flesus: important food fish of Europe
platyctenean: ctenophore have long tentacles and flattened body
Platypoecilus maculatus: small stocky Mexican fish; popular aquarium fish
Plautus alle: small short-billed auk abundant in Arctic regions
plecopteran: primitive winged insect with a flattened body; used as bait by fishermen; aquatic gilled larvae are carnivorous and live beneath stones
Plecotus townsendi: bat of western North America having extremely large ears
plectognath: tropical marine fishes having the teeth fused into a beak and thick skin covered with bony plates or spines
Plectophera: in some former classifications: name for the Ephemeroptera
Plectrophenax nivalis: white Arctic bunting
pleopod: one of the paired abdominal appendages of certain aquatic crustaceans that function primarily for carrying the eggs in females and are usually adapted for swimming
plesiosaur: extinct marine reptile with a small head on a long neck a short tail and four paddle-shaped limbs; of the Jurassic and Cretaceous
Plethodon cinereus: common salamander of eastern North America
Plethodon vehiculum: salamander of the Pacific coast of North America
pleurodont: an animal having teeth fused with the inner surface of the alveolar ridge without sockets
Pleuronectes platessa: large European food fish
Plicatoperipatus jamaicensis: a kind of onychophoran
Ploceus philippinus: common Indian weaverbird
Plott hound: a brindle-coated American hound used in hunting bears and wild boars
plough horse: a horse used to pull a plow
plover: any of numerous chiefly shorebirds of relatively compact build having straight bills and large pointed wings; closely related to the sandpipers
plumule: down feather of young birds; persists in some adult birds
Pluvianus aegyptius: African courser that feeds on insect parasites on crocodiles
Plymouth Rock: an American breed of domestic fowl
poacher: small slender fish (to 8 inches) with body covered by bony plates; chiefly of deeper northern Pacific waters
pocket mouse: any of various small nocturnal burrowing desert rodents with cheek pouches and long hind legs and tail
pocket rat: any of various rodents with cheek pouches
Podiceps cristatus: large Old World grebe with black ear tufts
Podiceps grisegena: large stocky grebe of circumpolar regions having a dark neck
Podiceps nigricollis: small grebe with yellow ear tufts and a black neck; found in Eurasia and southern Africa as well as western United States
Podiceps ruficollis: small European grebe
podicipitiform seabird: aquatic birds related to the loons
Podilymbus podiceps: American grebe having a black-banded whitish bill
Poecilocapsus lineatus: yellow or orange leaf bug with four black stripes down the back; widespread in central and eastern North America
Poecilogale albinucha: small slender burrowing muishond with white top of the head
Poephila castanotis: small Australian weaverbird with markings like a zebra's
pole horse: the horse having a starting position next to the inside rail in a harness race
pole horse: a draft horse harnessed alongside the shaft or pole of a vehicle
polecat: American musteline mammal typically ejecting an intensely malodorous fluid when startled; in some classifications put in a separate subfamily Mephitinae
police dog: any dog trained to assist police especially in tracking
poliovirus: the virus causing poliomyelitis
Polistes annularis: a variety of paper wasp
poll: a tame parrot
Pollachius pollachius: important food and game fish of northern seas (especially the northern Atlantic); related to cod
pollard: a usually horned animal that has either shed its horns or had them removed
pollinator: an insect that carries pollen from one flower to another
polliwog: a larval frog or toad
polo pony: a small agile horse specially bred and trained for playing polo
Polyborus cheriway audubonii: widespread from southern United States to Central America; rusty black with black-and-white breast and tail
Polyborus plancus: South American caracara
polychaete: chiefly marine annelids possessing both sexes and having paired appendages (parapodia) bearing bristles
Polydactylus virginicus: found along western Atlantic coast
Polyergus rufescens: small reddish slave-making ant species
Polygonia comma: anglewing butterfly with a comma-shaped mark on the underside of each hind wing
polymastigote: flagellates with several flagella
polymorph: an organism that can assume more than one adult form as in the castes of ants or termites
Polyodon spathula: primitive fish of the Mississippi valley having a long paddle-shaped snout
polyoma: a virus the can initiate various kinds of tumors in mice
polyp: one of two forms that coelenterates take (e.g. a hydra or coral): usually sedentary with a hollow cylindrical body usually with a ring of tentacles around the mouth
polyploid: (genetics) an organism or cell having more than twice the haploid number of chromosomes
Polyprion americanus: brown fish of the Atlantic and Mediterranean found around rocks and shipwrecks
Pomacentrus leucostictus: a blue and yellow damselfish of Bermuda and Florida and the West Indies
Pomatomus saltatrix: bluish warm-water marine food and game fish that follow schools of small fishes into shallow waters
Pomeranian: breed of very small compact long-haired dogs of the spitz type
Pomolobus pseudoharengus: shad-like food fish that runs rivers to spawn; often salted or smoked; sometimes placed in genus Pomolobus
Pomoxis annularis: a crappie that is white
Pomoxis nigromaculatus: a crappie that is black
pompano: any of several deep-bodied food fishes of western Atlantic and Gulf of Mexico
pond scum: free-floating freshwater green algae
pond-skater: long-legged bug that skims about on the surface of water
Pongo pygmaeus: large long-armed ape of Borneo and Sumatra having arboreal habits
pony: any of various breeds of small gentle horses usually less than five feet high at the shoulder
pony: a range horse of the western United States
pony: an informal term for a racehorse
poodle: an intelligent dog with a heavy curly solid-colored coat that is usually clipped; an old breed sometimes trained as sporting dogs or as performing dogs
Pooecetes gramineus: common North American finch noted for its evening song
Popillia japonica: small metallic green and brown beetle native to eastern Asia; serious plant pest in North America
popinjay: an archaic term for a parrot
porgy: important deep-bodied food and sport fish of warm and tropical coastal waters; found worldwide
porker: a pig fattened to provide meat
Poronotus triacanthus: small food fish of Atlantic coast
Porphyrio porphyrio: purple gallinule of southern Europe
Porphyrula martinica: American purple gallinule
porpoise: any of several small gregarious cetacean mammals having a blunt snout and many teeth
Portuguese man-of-war: large siphonophore having a bladderlike float and stinging tentacles
Porzana porzana: Eurasian rail of swamps and marshes
post horse: a horse kept at an inn or post house for use by mail carriers or for rent to travelers
Potamogale velox: amphibious African insectivorous mammal that resembles an otter
Potamophis striatula: in some classifications placed in genus Haldea; small reddish-grey snake of eastern North America
potato yellow-dwarf virus: the virus that produces stunting and yellowing of the leaves of potato plants
potoroo: Australian rat kangaroos
Potos caudivolvulus: arboreal fruit-eating mammal of tropical America with a long prehensile tail
potter bee: solitary bee that builds nests of mud or pebbles cemented together and attached to a plant
potter wasp: any of various solitary wasps that construct vase-shaped cells of mud for their eggs
pouter: one of a breed of pigeon that enlarge their crop until their breast is puffed out
poxvirus: any of a group of viruses that can cause pox diseases in vertebrates
PPLO: a mycoplasma resistant to antibiotics that causes a kind of pneumonia in humans
prairie chicken: brown mottled North American grouse of western prairies
prairie dog: any of several rodents of North American prairies living in large complex burrows having a barking cry
prancer: a mettlesome or fiery horse
prawn: shrimp-like decapod crustacean having two pairs of pincers; most are edible
praya: colonial siphonophore of up to 130 ft long
predator: any animal that lives by preying on other animals
preen gland: oil-secreting gland situated at the base of the tail in most birds
prehensor: the anterior pair of legs of a centipede that are modified to seize prey and inject venom from the toxicognaths
prey: animal hunted or caught for food
Priacanthus arenatus: brightly colored carnivorous fish of western Atlantic and West Indies waters
pricket: male deer in his second year
prickleback: small elongate fishes of shallow northern seas; a long dorsal fin consists entirely of spines
prickleback: small (2-4 inches) pugnacious mostly scaleless spiny-backed fishes of northern fresh and littoral waters having elaborate courtship; subjects of much research
primary: one of the main flight feathers projecting along the outer edge of a bird's wing
primate: any placental mammal of the order Primates; has good eyesight and flexible hands and feet
Priodontes giganteus: about three feet long exclusive of tail
Prionace glauca: slender cosmopolitan, pelagic shark; blue body shades to white belly; dangerous especially during maritime disasters
Prionotus carolinus: large searobin; found from Nova Scotia to Florida
Pristis pectinatus: commonly found in tropical bays and estuaries; not aggressive
probiotic: a beneficial bacterium found in the intestinal tract of healthy mammals; often considered to be a plant
proboscidean: massive herbivorous mammals having tusks and a long trunk
proboscis: a long flexible snout as of an elephant
procaryote: a unicellular organism having cells lacking membrane-bound nuclei; bacteria are the prime example but also included are blue-green algae and actinomycetes and mycoplasma
Procavia capensis: hyrax that lives in rocky areas
Procellaria aequinoctialis: large black petrel of southern seas having a white mark on the chin
procellariiform seabird: large long-winged bird with hooked bill and tubular nostrils that wanders the open seas
Prociphilus tessellatus: attacks alders
proconsul: an anthropoid ape of the genus Proconsul
Procyon cancrivorus: a South American raccoon
Procyon lotor: North American raccoon
procyonid: plantigrade carnivorous mammals
Progne subis: large North American martin of which the male is blue-black
prosimian: primitive primates having large ears and eyes and characterized by nocturnal habits
Prosopium cylindraceum: a whitefish with a bronze back; of northern North America and Siberia
protective covering: the tough natural covering of some organisms
Proteles cristata: striped hyena of southeast Africa that feeds chiefly on insects
Proteus anguinus: European aquatic salamander with permanent external gills that lives in caves
prothorax: the anterior part of an insect's thorax; bears the first pair of legs
protist: free-living or colonial organisms with diverse nutritional and reproductive modes
protoavis: most primitive avian type known; extinct bird of the Triassic having bird-like jaw and hollow limbs and breastbone with dinosaur-like tail and hind limbs
protoceratops: small horned dinosaur
protoctist: any of the unicellular protists
protoctist family: any of the families of Protoctista
protoctist genus: any genus of Protoctista
protoctist order: the order of protoctists
protohippus: Pliocene horse approaching donkeys in size
protomammal: probably warm-blooded; considered direct ancestor of mammals
prototherian: primitive oviparous mammals found only in Australia and Tasmania and New Guinea
protozoan: any of diverse minute acellular or unicellular organisms usually nonphotosynthetic
proturan: any of several minute primitive wingless and eyeless insects having a cone-shaped head; inhabit damp soil or decaying organic matter
Prunella modularis: small brownish European songbird
Psetta maxima: a large brownish European flatfish
Psettichthys melanostichus: a common flatfish of the Pacific coast of North America
Pseudaletia unipuncta: moth whose destructive larvae travel in multitudes
Pseudaletia unipuncta: noctuid moth larvae that travel in multitudes destroying especially grass and grain
Pseudechis porphyriacus: large semiaquatic snake of Australia; black above with red belly
Pseudemys concinna: large river turtle of the southern United States and northern Mexico
Pseudemys rubriventris: freshwater turtle of Chesapeake Bay tributaries having red markings on the lower shell
Pseudemys scripta: freshwater turtle of United States and South America; frequently raised commercially; some young sold as pets
Pseudococcus comstocki: Asiatic insect introduced accidentally into United States; pest on citrus and apple trees
Pseudococcus fragilis: destructive especially to citrus
pseudomonad: bacteria usually producing greenish fluorescent water-soluble pigment; some pathogenic for plants and animals
Pseudomonas pyocanea: a species of aerobic bacteria
Pseudomonas solanacearum: causes brown rot in tomatoes and potatoes and tobacco etc
Pseudopleuronectes americanus: important American food fish in the winter
pseudopod: temporary outgrowth used by some microorganisms as an organ of feeding or locomotion
Pseudoryx nghetinhensis: cow-like creature with the glossy coat of a horse and the agility of a goat and the long horns of an antelope; characterized as a cow that lives the life of a goat
psittacosaur: primitive dinosaur actually lacking horns and having only the beginning of a frill; long hind limbs and short forelimbs; may have been bipedal
Psittacula krameri: African parakeet
Psittacus erithacus: commonly domesticated grey parrot with red-and-black tail and white face; native to equatorial Africa
psocid: small winged insect living on the bark and leaves of trees and feeding on e.g. fungi and decaying plant matter
psocopterous insect: small soft-bodied insect with chewing mouthparts and either no wings or two pairs
psychodid: a fly of the family Psychodidae
ptarmigan: large Arctic and subarctic grouse with feathered feet and usually white winter plumage
Pternohyla fodiens: terrestrial burrowing nocturnal frog of grassy terrain and scrub forests having very hard upper surface of head; of the United States southwest
Pterocles alchata: sandgrouse of Europe and Africa having elongated middle tail feathers
Pterocles indicus: sandgrouse of India
Pterocnemia pennata: smaller of two tall fast-running flightless birds similar to ostriches but three-toed; found from Peru to Strait of Magellan
pterodactyl: extinct flying reptile
Pteropus capestratus: a variety of fruit bat
Pteropus hypomelanus: a variety of fruit bat
Ptilonorhynchus violaceus: of southeast Australia; male is glossy violet blue; female is light grey-green
Ptloris paradisea: velvety black Australian bird of paradise with green and purple iridescence on head and tail
Ptychozoon homalocephalum: a gecko that has membranous expansions along the sides of its body and limbs and tail that enable it to glide short distances
puffbird: brownish tropical American bird having a large head with fluffed out feathers
puffin: any of two genera of northern seabirds having short necks and brightly colored compressed bills
Puffinus puffinus: small black-and-white shearwater common in the northeastern Atlantic
pug: small compact smooth-coated breed of Asiatic origin having a tightly curled tail and broad flat wrinkled muzzle
Pulex irritans: the most common flea attacking humans
pullet: young hen usually less than a year old
pup: young of any of various canines such as a dog or wolf
pupa: an insect in the inactive stage of development (when it is not feeding) intermediate between larva and adult
puppy: a young dog
pureblood: a pedigreed animal of unmixed lineage; used especially of horses
purple bacteria: free-living Gram-negative pink to purplish-brown bacteria containing bacteriochlorophyll
purple gallinule: gallinules with showy purplish plumage
pus-forming bacteria: bacteria that produce pus
pycnogonid: any of various small spiderlike marine arthropods having small thin bodies and long slender legs
Pygoscelis adeliae: medium-sized penguins occurring in large colonies on the Adelie Coast of Antarctica
Pylodictus olivaris: large catfish of central United States having a flattened head and projecting jaw
pyralid: usually tropical slender-bodied long-legged moth whose larvae are crop pests
Pyrausta nubilalis: larva of the European corn borer moth; a serious pest of maize
Pyrocephalus rubinus mexicanus: tropical American flycatcher found as far north as southern Texas and Arizona; adult male has bright scarlet and black plumage
Pyrophorus noctiluca: tropical American click beetle having bright luminous spots
Pyrrhula pyrrhula: common European finch mostly black and white with red throat and breast
Pyrrhuloxia sinuata: crested grey-and-red bird of southwest United States and Mexico
python: large Old World boas
Python molurus: very large python of southeast Asia
Python reticulatus: of southeast Asia and East Indies; the largest snake in the world
Python sebae: very large python of tropical and southern Africa
quack-quack: child's word for a duck
quadruped: an animal especially a mammal having four limbs specialized for walking
quail: small gallinaceous game birds
quarter horse: a small powerful horse originally bred for sprinting in quarter-mile races in Virginia
queen: the only fertile female in a colony of social insects such as bees and ants and termites; its function is to lay eggs
queen bee: fertile egg-laying female bee
queen: an especially large mole rat and the only member of a colony of naked mole rats to bear offspring which are sired by only a few males
queen: female cat
quetzal: large trogon of Central America and South America having golden-green and scarlet plumage
quill: a stiff hollow protective spine on a porcupine or hedgehog
Quiscalus quiscula: eastern United States grackle
rabbit ears: the long ears of a rabbit
raccoon: an omnivorous nocturnal mammal native to North America and Central America
racer: an animal that races
racer: slender fast-moving North American snakes
Rachycentron canadum: large dark-striped tropical food and game fish related to remoras; found worldwide in coastal to open waters
radiolarian: protozoa with amoeba-like bodies and radiating filamentous pseudopods
rail: any of numerous widely distributed small wading birds of the family Rallidae having short wings and very long toes for running on soft mud
Raja batis: common European skate used as food
Raja erinacea: most plentiful skate in North American inshore waters in summer; to 21 inches
Raja laevis: one of the largest skates (to 5 feet); an active skate easy to hook
Raja radiata: cold-water bottom fish with spines on the back; to 40 inches
ram: uncastrated adult male sheep
Rambouillet: hardy sheep developed from the merino producing both good mutton and fine wool
Rana cascadae: mountain frog found near water; of United States Northwest to California
Rana catesbeiana: largest North American frog; highly aquatic with a deep-pitched voice
Rana clamitans: similar to bullfrog; found in or near marshes and ponds; of United States and Canada
Rana goliath: largest living frog; up to a foot and weighing up to 10 lbs; Africa
Rana palustris: a meadow frog of eastern North America
Rana pipiens: common North American green or brownish frog having white-edged dark oval spots
Rana sylvatica: wide-ranging light-brown frog of moist North American woodlands especially spruce
Rana tarahumarae: Mexican frog found within a jump or two of water
Rana temporaria: a common semiterrestrial European frog
range animal: any animal that lives and grazes in the grassy open land of western North America (especially horses, cattle, sheep)
Rangifer arcticus: of tundra of northern Canada; in some classifications included in the species Rangifer tarandus
Rangifer caribou: any of several large caribou living in coniferous forests of southern Canada; in some classifications included in the species Rangifer tarandus
Rangifer tarandus: Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America
ranid: insectivorous usually semiaquatic web-footed amphibian with smooth moist skin and long hind legs
Raphicerus campestris: small plains antelope of southeastern Africa
Raphus cucullatus: extinct heavy flightless bird of Mauritius related to pigeons
rat: any of various long-tailed rodents similar to but larger than a mouse
rat snake: any of various nonvenomous rodent-eating snakes of North America and Asia
rat terrier: any of several breeds of terrier developed to catch rats
rattle: loosely connected horny sections at the end of a rattlesnake's tail
rattler: pit viper with horny segments at the end of the tail that rattle when shaken
Rattus norvegicus: common domestic rat; serious pest worldwide
Rattus rattus: common household pest originally from Asia that has spread worldwide
ray: any of the stiff bony spines in the fin of a fish
ray: cartilaginous fishes having horizontally flattened bodies and enlarged winglike pectoral fins with gills on the underside; most swim by moving the pectoral fins
razor fish: any of several small wrasses with compressed sharp-edged heads of the West Indies and Mediterranean
razorback: a mongrel hog with a thin body and long legs and a ridged back; a wild or semi-wild descendant of improved breeds; found chiefly in the southeastern United States
razorback: any of several baleen whales of the family Balaenopteridae having longitudinal grooves on the throat and a small pointed dorsal fin
recombinant: a cell or organism in which genetic recombination has occurred
red algae: marine algae in which the chlorophyll is masked by a red or purplish pigment; source of agar and carrageenan
red coral: corals of especially the Mediterranean having pink or red color used for ornaments and jewelry
red poll: hornless short-haired breed of beef and dairy cattle
redback vole: any of several voles of mountainous regions of Eurasia and America
redbone: a speedy red or red-and-tan American hound
redfish: male salmon that has recently spawned
redhorse: North American sucker with reddish fins
redstart: European songbird with a reddish breast and tail; related to Old World robins
reeve: female ruff
Regalecus glesne: thin deep-water tropical fish 20 to 30 feet long having a red dorsal fin
Regulus calendula: American kinglet with a notable song and in the male a red crown patch
Regulus regulus: European kinglet with a black-bordered yellow crown patch
Regulus satrata: American golden-crested kinglet
Remilegia australis: large blue Pacific remora that attaches to whales and dolphins
remora: marine fishes with a flattened elongated body and a sucking disk on the head for attaching to large fish or moving objects
remount: a fresh horse especially (formerly) to replace one killed or injured in battle
Reoviridae: a family of arboviruses carried by arthropods
reovirus: any of a group of non-arboviruses including the rotavirus causing infant enteritis
reptile family: a family of reptiles
reptile genus: a genus of reptiles
reptile: any cold-blooded vertebrate of the class Reptilia including tortoises, turtles, snakes, lizards, alligators, crocodiles, and extinct forms
requiem shark: any of numerous sharks from small relatively harmless bottom-dwellers to large dangerous oceanic and coastal species
respiratory syncytial virus: a paramyxovirus that forms syncytia in tissue culture and that is responsible for severe respiratory diseases such as bronchiolitis and bronchial pneumonia (especially in children)
Reticulitermes flanipes: destructive United States termite
Reticulitermes lucifugus: destructive European termite
reticulum: the second compartment of the stomach of a ruminant
retriever: a dog with heavy water-resistant coat that can be trained to retrieve game
retrovirus: any of a group of viruses that contain two single-strand linear RNA molecules per virion and reverse transcriptase (RNA to DNA); the virus transcribes its RNA into a cDNA provirus that is then incorporated into the host cell
Reynard: a conventional name for a fox used in tales following usage in the old epic `Reynard the Fox'
Rhabdoviridae: a family of arborviruses carried by arthropods
rhabdovirus: any of a group of arboviruses including those causing rabies
Rhagoletis pomonella: larvae bore into and feed on apples
Rhea americana: larger of two tall fast-running flightless birds similar to ostriches but three-toed; found from Brazil to Patagonia
Rhincodon typus: large spotted shark of warm surface waters worldwide; resembles a whale and feeds chiefly on plankton
rhino: massive powerful herbivorous odd-toed ungulate of southeast Asia and Africa having very thick skin and one or two horns on the snout
Rhinoceros antiquitatis: extinct thick-haired species of Arctic regions
rhinoceros beetle: any of various large chiefly tropical beetles having horns on the head; pest on coconuts
Rhinoceros unicornis: having one horn
Rhinonicteris aurantius: a common bat of northwestern Australia having orange or yellow fur
Rhinoptera bonasus: large ray found along eastern coast of North America
rhinovirus: any of a group of picornaviruses that are responsible for many upper respiratory infections
rhizopod: protozoa characterized by a pseudopod
Rhode Island red: American breed of heavy-bodied brownish-red general-purpose chicken
Rhodesian ridgeback: a powerful short-haired African hunting dog having a crest of reversed hair along the spine
Rhodymenia palmata: coarse edible red seaweed
Rhyacotriton olympicus: small large-eyed semiaquatic salamander of the United States Northwest
Rhynchoelaps australis: small venomous but harmless snake marked with black-and-white on red
ribbonfish: marine fish having a long compressed ribbonlike body
Richardson ground squirrel: of sagebrush and grassland areas of western United States and Canada
Richmondena Cardinalis: crested thick-billed North American finch having bright red plumage in the male
rickettsia: any of a group of very small rod-shaped bacteria that live in biting arthropods (as ticks and mites) and cause disease in vertebrate hosts; they cause typhus and other febrile diseases in human beings
ridgel: a colt with undescended testicles
ridley: a marine turtle
right whale: large Arctic whalebone whale; allegedly the `right' whale to hunt because of its valuable whalebone and oil
righteye flounder: flounders with both eyes on the right side of the head
ring snake: any of numerous small nonvenomous North American snakes with a yellow or orange ring around the neck
ringlet: any of various butterflies belonging to the family Satyridae
ringtail: an immature golden eagle
Riparia riparia: swallow of the northern hemisphere that nests in tunnels dug in clay or sand banks
river dolphin: any of several long-snouted usually freshwater dolphins of South America and southern Asia
rivulus: found in small streams of tropical America; often kept in aquariums; usually hermaphroditic
roadkill: the dead body of an animal that has been killed on a road by a vehicle
roan: a horse having a brownish coat thickly sprinkled with white or gray
robalo: a kind of percoid fish
robber frog: small terrestrial frog of tropical America
Roccus saxatilis: marine food and game fish with dark longitudinal stripes; migrates upriver to spawn; sometimes placed in the genus Morone
Rock Cornish: small plump hybrid developed by crossbreeding Plymouth Rock and Cornish fowl
rock kangaroo: slender long-legged Australian wallabies living in caves and rocky areas
rockfish: marine food fish found among rocks along the northern coasts of Europe and America
rockweed: coarse brown seaweed growing on rocks exposed at low tide
Rocky Mountain bighorn: wild sheep of mountainous regions of western North America having massive curled horns
Rocky Mountain goat: sure-footed mammal of mountainous northwestern North America
Rocky Mountain whitefish: whitefish of the western United States and Canada
rod: any rod-shaped bacterium
Rodolia cardinalis: native to Australia; introduced elsewhere to control scale insects
roe: the eggs or egg-laden ovary of a fish
roe: the egg mass or spawn of certain crustaceans such as the lobster
roe: eggs of female fish
roebuck: male roe deer
rogue elephant: a wild and vicious elephant separated from the herd
roller: Old World bird that tumbles or rolls in flight; related to kingfishers
roller: pigeon that executes backward somersaults in flight or on the ground
rostrum: beaklike projection of the anterior part of the head of certain insects such as e.g. weevils
rotavirus: the reovirus causing infant enteritis
rotifer: minute aquatic multicellular organisms having a ciliated wheel-like organ for feeding and locomotion; constituents of freshwater plankton
Rottweiler: German breed of large vigorous short-haired cattle dogs
rough fish: any fish useless for food or sport or even as bait
rove beetle: active beetle typically having predatory or scavenging habits
royal: stag with antlers of 12 or more branches
ruminant: any of various cud-chewing hoofed mammals having a stomach divided into four (occasionally three) compartments
Rupicapra rupicapra: hoofed mammal of mountains of Eurasia having upright horns with backward-hooked tips
Rupicola peruviana: bird of the Andes similar to Rupicola rupicola
Rupicola rupicola: tropical bird of northern South America the male having brilliant red or orange plumage and an erectile disklike crest
Russian wolfhound: tall fast-moving dog breed
rust mite: any of several varieties of mite that burrow into plants and cause a reddish-brown discoloration on the leaves or fruit
Rutilus rutilus: European freshwater food fish having a greenish back
Ruvettus pretiosus: very large deep-water snake mackerel
sabertooth: any of many extinct cats of the Old and New Worlds having long swordlike upper canine teeth; from the Oligocene through the Pleistocene
saddle: posterior part of the back of a domestic fowl
saddle feather: a long narrow feather on the back (saddle) of a domestic fowl
sagitta: any arrowworm of the genus Sagitta
Sagittarius serpentarius: large long-legged African bird of prey that feeds on reptiles
Saiga tatarica: goat-like antelope of central Eurasia having a stubby nose like a proboscis
sailfish: large pelagic game fish having an elongated upper jaw and long dorsal fin that resembles a sail
Saimiri sciureus: small long-tailed monkey of Central American and South America with greenish fur and black muzzle
Saint Bernard: a Swiss alpine breed of large powerful dog with a thick coat of hair used as a rescue dog
saki: small arboreal monkey of tropical South America with long hair and bushy nonprehensile tail
salamander: any of various typically terrestrial amphibians that resemble lizards and that return to water only to breed
Salamandra atra: ovoviviparous amphibian of the Alps
Salamandra maculosa: European salamander having dark skin with usually yellow spots
Salmo gairdneri: found in Pacific coastal waters and streams from lower California to Alaska
Salmo trutta: speckled trout of European rivers; introduced in North America
salmon: any of various large food and game fishes of northern waters; usually migrate from salt to fresh water to spawn
salmonella: rod-shaped Gram-negative enterobacteria; cause typhoid fever and food poisoning; can be used as a bioweapon
Salmonella enteritidis: a form of salmonella that causes gastroenteritis in humans
Salmonella typhimurium: a form of salmonella that causes food poisoning in humans
Salmonella typhosa: a form of salmonella that causes typhoid fever
salmonid: soft-finned fishes of cold and temperate waters
salp: minute floating marine tunicate having a transparent body with an opening at each end
Salpinctes obsoletus: wren inhabiting badlands and mesa country of western United States and Mexico
Saluki: old breed of tall swift keen-eyed hunting dogs resembling greyhounds; from Egypt and southwestern Asia
Salvelinus alpinus: small trout of northern waters; landlocked populations in Quebec and northern New England
Salvelinus fontinalis: North American freshwater trout; introduced in Europe
Salvelinus namaycush: large fork-tailed trout of lakes of Canada and the northern United States
Samia cynthia: large green silkworm of the cynthia moth
Samia walkeri: large Asiatic moth introduced into the United States; larvae feed on the ailanthus
Samoyede: Siberian breed of white or cream-colored dog of the spitz family
sand cat: a desert wildcat
sand dab: small food fishes of the Pacific coast of North America
sand dollar: flattened disklike sea urchins that live on sandy bottoms
sand grouse: pigeon-like bird of arid regions of the Old World having long pointed wings and tail and precocial downy young
sand rat: small nearly naked African mole rat of desert areas
sand snake: small North American burrowing snake
sand stargazer: small pallid fishes of shoal tropical waters of North America and South America having eyes on stalks atop head; they burrow in sand to await prey
sandfish: either of two small silvery scaleless fishes of the northern Pacific that burrow into sand
sandpiper: any of numerous usually small wading birds having a slender bill and piping call; closely related to the plovers
Santa Gertrudis: Brahman and shorthorn crossbreed of red cattle; hardy in hot regions
sapsucker: small American woodpecker that feeds on sap from e.g. apple and maple trees
sarcocystidean: parasite of the muscles of vertebrates
sarcodine: protozoa that move and capture food by forming pseudopods
Sarcophaga carnaria: fly whose larvae feed on carrion or the flesh of living animals
Sarcophilus hariisi: small ferocious carnivorous marsupial having a mostly black coat and long tail
Sarcorhamphus papa: large black-and-white vulture of South America and Central America; have colorful wattles and wartlike protuberances on head and neck
Sarda chiliensis: common bonito of Pacific coast of the Americas; its dark oily flesh cans well
Sardina pilchardus: small fishes found in great schools along coasts of Europe; smaller and rounder than herring
sardine: any of various small edible herring or related food fishes frequently canned
Sardinops caerulea: small pilchards common off the pacific coast of North America
Sargassum bacciferum: brown algae with rounded bladders forming dense floating masses in tropical Atlantic waters as in the Sargasso Sea
sargassum fish: small fantastically formed and colored fishes found among masses of sargassum
Saturnia pavonia: large moth of temperate forests of Eurasia having heavily scaled transparent wings
saturniid: large brightly colored and usually tropical moth; larvae spin silken cocoons
saurian: any of various reptiles of the suborder Sauria which includes lizards; in former classifications included also the crocodiles and dinosaurs
saurischian: herbivorous or carnivorous dinosaur having a three-pronged pelvis like that of a crocodile
Sauromalus obesus: a herbivorous lizard that lives among rocks in the arid parts of southwestern United States and Mexico
sauropod: very large herbivorous dinosaur of the Jurassic and Cretaceous having a small head a long neck and tail and five-toed limbs; largest known land animal
sausage dog: informal term
sawfish: primitive ray with sharp teeth on each edge of a long flattened snout
sawfly: insect whose female has a saw-like ovipositor for inserting eggs into the leaf or stem tissue of a host plant
sawyer: any of several beetles whose larvae bore holes in dead or dying trees especially conifers
Saxicola rubetra: brown-and-buff European songbird of grassy meadows
Saxicola torquata: common European chat with black plumage and a reddish-brown breast
Sayornis phoebe: small dun-colored North American flycatcher
scad: any of a number of fishes of the family Carangidae
scale: a flattened rigid plate forming part of the body covering of many animals
scale insect: small homopterous insect that usually lives and feeds on plants and secretes a protective waxy covering
scallop shell: a shell of a scallop
Scaphiopus bombifrons: this spadefoot toad lives in plains and hills and river bottoms in areas of low rainfall east of the Rocky Mountains
Scaphiopus hammondii: this spadefoot toad live in California
Scaphiopus multiplicatus: this spadefoot toad lives in the southwestern United States
scaphopod: burrowing marine mollusk
scapular: a feather covering the shoulder of a bird
scarabaean: any of numerous species of stout-bodied beetles having heads with horny spikes
Scarabaeus sacer: scarabaeid beetle considered divine by ancient Egyptians
Scardinius erythrophthalmus: European freshwater fish resembling the roach
Scartella cristata: inhabits both coasts of tropical Atlantic
scavenger: any animal that feeds on refuse and other decaying organic matter
Sceloglaux albifacies: almost extinct owl of New Zealand
Sceloporus graciosus: a ground dweller that prefers open ground and scattered low bushes; of United States west between Rocky and Sierra Nevada Mountains
Sceloporus occidentalis: common western lizard; seen on logs or rocks
Sceloporus undulatus: small active lizard of United States and north to British Columbia
schipperke: breed of small stocky black dogs originally used as watchdogs on boats in the Netherlands and Belgium
Schizopoda: in former classifications a division of Malacostraca; superseded by the orders Mysidacea and Euphausiacea
schnauzer: old German breed of sturdy black or greyish wire-haired terriers having a blunt muzzle ranging in size from fairly small to very large; used as ratters and guard dogs or police dogs
schrod: young Atlantic cod or haddock especially one split and boned for cooking
Sciaena antarctica: large important food fish of Australia; almost indistinguishable from the maigre
Sciaena aquila: large European marine food fish
sciaenid: widely distributed family of carnivorous percoid fishes having a large air bladder used to produce sound
Sciaenops ocellatus: large edible fish found off coast of United States from Massachusetts to Mexico
scincid: alert agile lizard with reduced limbs and an elongated body covered with shiny scales; more dependent on moisture than most lizards; found in tropical regions worldwide
Sciurus carolinensis: common medium-large squirrel of eastern North America; now introduced into England
Sciurus griseus: large grey squirrel of far western areas of United States
Sciurus niger: exceptionally large arboreal squirrel of eastern United States
Sciurus vulgaris: common reddish-brown squirrel of Europe and parts of Asia
sclerite: hard plate or element of the exoskeleton of some arthropods
Scleropages leichardti: a species of large fish found in Australian rivers
Scolopax rusticola: short-legged long-billed migratory Old World woodcock
Scolytus multistriatus: a vector of the fungus causing Dutch elm disease
Scomber japonicus: small mackerel found nearly worldwide
Scomber scombrus: important food fish of the northern Atlantic and Mediterranean; its body is greenish-blue with dark bars and small if any scales
Scomberesox saurus: slender long-beaked fish of temperate Atlantic waters
Scomberomorus cavalla: large mackerel with long pointed snout; important food and game fish of the eastern Atlantic coast southward to Brazil
Scomberomorus maculatus: a large commercially important mackerel of the Atlantic coastal waters of North America
Scomberomorus regalis: large edible mackerel of temperate United States coastal Atlantic waters
Scomberomorus sierra: a Spanish mackerel of western North America
scombroid: important marine food and game fishes found in all tropical and temperate seas; some are at least partially endothermic and can thrive in colder waters
scooter: large black diving duck of northern parts of the northern hemisphere
Scophthalmus aquosus: very thin translucent flounder of the Atlantic coast of North America
Scophthalmus rhombus: European food fish
scops owl: any of several small owls having ear tufts and a whistling call
Scorpaena grandicornis: a kind of scorpionfish
scorpaenid: any of numerous carnivorous usually bottom-dwelling warm-water marine fishes found worldwide but most abundant in the Pacific
scorpaenoid: fishes having the head armored with bony plates
scorpion: arachnid of warm dry regions having a long segmented tail ending in a venomous stinger
scorpion fish: marine fishes having a tapering body with an armored head and venomous spines
scorpion fly: any of various mecopterous insects of the family Panorpidae of the northern hemisphere having a long beak and long antennae; males have a tail like that of a scorpion except it is not venomous
scorpion shell: any of numerous tropical marine snails that as adults have the outer lip of the aperture produced into a series of long curved spines
Scottish deerhound: very large and tall rough-coated dog bred for hunting deer; known as the royal dog of Scotland
Scottish terrier: old Scottish breed of small long-haired usually black terrier with erect tail and ears
screamer: gooselike aquatic bird of South America having a harsh trumpeting call
screech owl: any owl that has a screeching cry
scrub bird: small fast-running Australian bird resembling a wren and frequenting brush or scrub
sculpin: any of numerous spiny large-headed usually scaleless scorpaenoid fishes with broad mouths
scut: a short erect tail
scute: large bony or horny plate as on an armadillo or turtle or the underside of a snake
Scutigera coleoptrata: long-legged centipede common in damp places as e.g. cellars
Scutigerella immaculata: minute arthropod often infesting the underground parts of truck-garden and greenhouse crops
scyphozoan: any of various usually free-swimming marine coelenterates having a gelatinous medusoid stage as the dominant phase of its life cycle
sea bass: any of various food and sport fishes of the Atlantic coast of the United States having an elongated body and long spiny dorsal fin
sea bird: a bird that frequents coastal waters and the open ocean: gulls; pelicans; gannets; cormorants; albatrosses; petrels; etc.
sea catfish: any of numerous marine fishes most of which are mouthbreeders; not used for food
sea chub: schooling fishes mostly of Indian and western Pacific oceans; two species in western Atlantic
sea cow: any of two families of large herbivorous aquatic mammals with paddle-shaped tails and flipper-like forelimbs and no hind limbs
sea duck: any of various large diving ducks found along the seacoast: eider; scoter; merganser
sea eagle: any of various large eagles that usually feed on fish
sea fan: corals having a treelike or fan-shaped horny skeleton
sea feather: corals forming featherlike colonies
sea gooseberry: ctenophore having a rounded body with longitudinal rows of cilia
sea horse: small fish with horse-like heads bent sharply downward and curled tails; swim in upright position
sea horse: either of two large northern marine mammals having ivory tusks and tough hide over thick blubber
sea lily: crinoid with delicate radiating arms and a stalked body attached to a hard surface
sea lion: any of several large eared seals of the northern Pacific related to fur seals but lacking their valuable coat
sea louse: marine isopod crustacean
sea moss: any of various red algae having graceful rose to purple fronds (e.g. dulse or carrageen)
sea mouse: any of several large worms having a broad flattened body with a mat of coarse hairs covering the back
sea pen: fleshy featherlike warm-water colonies
sea robin: American gurnard; mostly found in bays and estuaries
sea snake: any of numerous venomous aquatic viviparous snakes having a fin-like tail; of warm littoral seas; feed on fish which they immobilize with quick-acting venom
sea squirt: ascidian that can contract its body and eject streams of water
sea star: echinoderms characterized by five arms extending from a central disk
sea tang: any of various coarse seaweeds
sea tangle: any of various kelps especially of the genus Laminaria
sea trout: silvery marine variety of brown trout that migrates to fresh water to spawn
sea trout: any of several sciaenid fishes of North American coastal waters
sea urchin: shallow-water echinoderms having soft bodies enclosed in thin spiny globular shells
sea wrack: growth of marine vegetation especially of the large forms such as rockweeds and kelp
seagrass: any of various seaweeds that grow underwater in shallow beds
seal: any of numerous marine mammals that come on shore to breed; chiefly of cold regions
Sealyham terrier: a wire-haired terrier with short legs that was first bred in Sealyham
seashell: the shell of a marine organism
seasnail: any of several creeping marine gastropods with a spirally coiled shell: whelks; tritons; moon shells; neritids
Seattle Slew: thoroughbred that won the triple crown in 1977
seaweed: plant growing in the sea, especially marine algae
Sebastodes caurinus: a rockfish of the Pacific coastal waters of North America
Sebastodes marinus: large fish of northern Atlantic coasts of America and Europe
Sebastodes miniatus: a commercially important fish of the Pacific coast of North America
Sebastodes ruberrimus: a large fish of the Pacific coast of North America
Secretariat: thoroughbred that won the triple crown in 1973
seed beetle: a small beetle that infests the seeds of legumes
seed oyster: a young oyster especially of a size for transplantation
Seeing Eye dog: (trademark) a guide dog trained to guide a blind person
Seiurus aurocapillus: American warbler; builds a dome-shaped nest on the ground
seizure-alert dog: a dog that can alert or assist people with seizure disorders
Selar crumenophthalmus: of Atlantic coastal waters; commonly used for bait
Selenarctos thibetanus: bear with a black coat living in central and eastern Asia
Selene setapinnis: any of several silvery marine fishes with very flat bodies
Selene vomer: similar to moonfish but with eyes high on the truncated forehead
Semnopithecus entellus: langur of southern Asia; regarded as sacred in India
Sennenhunde: any of four Swiss breeds
sensory hair: a long stiff hair growing from the snout or brow of most mammals as e.g. a cat
sericterium: silk-producing gland of insects (especially of a silkworm) or spiders
serin: any of various brown and yellow finches of parts of Europe
Serinus canaria: native to the Canary Islands and Azores; popular usually yellow cage bird noted for its song
Seriola dorsalis: game fish of southern California and Mexico having a yellow tail fin
Seriola grandis: large game fish of Australia and New Zealand
Seriola zonata: fish having the habit of following ships; found in North American and South American coastal waters
Seriphus politus: silvery and bluish drumfish of shallow California coastal waters
serow: short-horned dark-coated goat antelope of mountain areas of southern and southeastern Asia
serranid: marine food sport fishes mainly of warm coastal waters
Serranus subligarius: found in warm shallow waters of western Atlantic
Serratia marcescens: the type species of the genus Serratia; a species found in water and soil and milk and foods and insects; can cause infections of the endocardium and blood and wounds and urinary tract and respiratory tract; has been tested as a bioweapon
sertularian: feathery colony of long-branched stems bearing stalkless paired polyps
seta: a stiff hair or bristle
Setophaga ruticilla: flycatching warbler of eastern North America the male having bright orange on sides and wings and tail
setter: a long-haired dog formerly trained to crouch on finding game but now to point
sewer rat: brown rat commonly found in sewers
shad: herring-like food fishes that migrate from the sea to fresh water to spawn
shark: any of numerous elongate mostly marine carnivorous fishes with heterocercal caudal fins and tough skin covered with small toothlike scales
shearwater: long-winged oceanic bird that in flight skims close to the waves
sheep: woolly usually horned ruminant mammal related to the goat
sheep dog: any of various usually long-haired breeds of dog reared to herd and guard sheep
sheep frog: mostly of Central America
sheldrake: Old World gooselike duck slightly larger than a mallard with variegated mostly black-and-white plumage and a red bill
shelduck: female sheldrake
shell: the hard largely calcareous covering of a mollusc or a brachiopod
Shetland pony: breed of very small pony with long shaggy mane and tail
Shetland sheep dog: a small sheepdog resembling a collie that was developed in the Shetland Islands
shigella: rod-shaped Gram-negative enterobacteria; some are pathogenic for warm-blooded animals; can be used as a bioweapon
Shigella dysentariae: a bacillus that causes dysentery
Shih-Tzu: a Chinese breed of small dog similar to a Pekingese
shiner: any of numerous small silvery North American cyprinid fishes especially of the genus Notropis
shipworm: wormlike marine bivalve that bores into wooden piers and ships by means of drill-like shells
shire: British breed of large heavy draft horse
shrew mole: slender mole having a long snout and tail
shrew: small mouselike mammal with a long snout; related to moles
shrike: any of numerous Old World birds having a strong hooked bill that feed on smaller animals
shrimp: small slender-bodied chiefly marine decapod crustaceans with a long tail and single pair of pincers; many species are edible
shrimpfish: slender tropical shallow-water East Indian fish covered with transparent plates
Sialis lutaria: dark-colored insect having predaceous aquatic larvae
Siamese cat: a slender short-haired blue-eyed breed of cat having a pale coat with dark ears paws face and tail tip
Siberian husky: breed of sled dog developed in northeastern Siberia; they resemble the larger Alaskan malamutes
sickle feather: one of the long curved tail feathers of a rooster
Sigmodon hispidus: destructive long-haired burrowing rat of southern North America and Central America
sild: any of various young herrings (other than brislings) canned as sardines in Norway
silkworm: the commercially bred hairless white caterpillar of the domestic silkworm moth which spins a cocoon that can be processed to yield silk fiber; the principal source of commercial silk
silkworm seed: eggs of a silkworm
silurid: Old World freshwater catfishes having naked skin and a long anal fin more or less merged with the eellike caudal fin
silver fox: red fox in the color phase when its pelt is tipped with white
silverback: an adult male gorilla with grey hairs across the back
silverfish: a silvery variety of Carassius auratus
silverside: small fishes having a silver stripe along each side; abundant along the Atlantic coast of the United States
silverspot: butterfly with silver spots on the underside of the hind wings
Silvia atricapilla: small brownish-grey warbler with a black crown
simian: an ape or monkey
Sinornis: sparrow-sized fossil bird of the Jurassic period to the Cretaceous period having a keeled breastbone and vestigial tail; found in China; considered possibly the second most primitive of all birds
siphon: a tubular organ in an aquatic animal (especially in mollusks) through which water can be taken in or expelled
siphonophore: a floating or swimming oceanic colony of polyps often transparent or showily colored
Sir Barton: thoroughbred that won the triple crown in 1919
sire: male parent of an animal especially a domestic animal such as a horse
siren: eellike aquatic North American salamander with small forelimbs and no hind limbs; have permanent external gills
Sistrurus catenatus: pygmy rattlesnake found in moist areas from the Great Lakes to Mexico; feeds on mice and small amphibians
Sistrurus miliaris: small pygmy rattlesnake
Sitophylus oryzae: brown weevil that infests stored grain especially rice
Sitotroga cerealella: small moth whose larvae feed on kernels of stored grains
Sitta canadensis: bluish-grey nuthatch with reddish breast; of northern coniferous forests
Sitta carolinensis: bluish-grey nuthatch with black head and white breast; of eastern North America
Sivapithecus: fossil primates found in India
skate: large edible rays having a long snout and thick tail with pectoral fins continuous with the head; swim by undulating the edges of the pectoral fins
skeleton shrimp: small amphipod crustacean having a grotesque form suggestive of the praying mantis; found chiefly on seaweed
skimmer: gull-like seabird that flies along the surface of the water with an elongated lower mandible immersed to skim out food
Skye terrier: Scottish breed of terrier with shaggy hair and long low body with short legs; native to the Isle of Skye
slater: any of various small terrestrial isopods having a flat elliptical segmented body; found in damp habitats
slave ant: any of various ants captured as larvae and enslaved by another species
slave-maker: an ant that attacks colonies of other ant species and carries off the young to be reared as slave ants
sled dog: a dog trained to draw a sled usually in a team
sleeper: tropical fish that resembles a goby and rests quietly on the bottom in shallow water
slender salamander: any of several small slim salamanders of the Pacific coast of the United States
sloth: any of several slow-moving arboreal mammals of South America and Central America; they hang from branches back downward and feed on leaves and fruits
slow virus: a virus that remains dormant in the body for a long time before symptoms appear
slug: any of various terrestrial gastropods having an elongated slimy body and no external shell
smallpox virus: the virus that causes smallpox in humans; can be used as a bioweapon
smelt: small trout-like silvery marine or freshwater food fishes of cold northern waters
Smiledon californicus: North American sabertooth; culmination of sabertooth development
smooth dogfish: small bottom-dwelling shark found along both Atlantic coasts
smooth-haired fox terrier: a fox terrier with smooth hair
snail: freshwater or marine or terrestrial gastropod mollusk usually having an external enclosing spiral shell
snakefly: predatory insect of western North America having a long necklike prothorax
snapper: any of several large sharp-toothed marine food and sport fishes of the family Lutjanidae of mainly tropical coastal waters
snapping turtle: large aggressive freshwater turtle with powerful jaws
snipe: Old or New World straight-billed game bird of the sandpiper family; of marshy areas; similar to the woodcocks
snook: large tropical American food and game fishes of coastal and brackish waters; resemble pike
snout beetle: small weevil having a prolonged snout; destructive to e.g. grains and nuts
snow goose: blue goose in the white color phase
soapfish: fishes with slimy mucus-covered skin; found in the warm Atlantic coastal waters of America
social insect: an insect that lives in a colony with other insects of the same species
soft scale: an insect active in all stages
soft-coated wheaten terrier: Irish breed of medium-sized terrier with an abundant coat any shade of wheat and very hairy head and muzzle
soft-shell crab: edible crab that has recently molted and not yet formed its new shell
soldier: a wingless sterile ant or termite having a large head and powerful jaws adapted for defending the colony
soldierfish: the larger squirrelfishes
sole: right-eyed flatfish; many are valued as food; most common in warm seas especially European
Solea lascaris: small European sole
solitaire: a dull grey North American thrush noted for its beautiful song
Solo man: early man of late Pleistocene; skull resembles that of Neanderthal man but with smaller cranial capacity; found in Java
songbird: any bird having a musical call
Sonora semiannulata: small shy brightly-ringed terrestrial snake of arid or semiarid areas of western North America
Sorex araneus: common American shrew
Sorex cinereus: commonest shrew of moist habitats in North America
sorrel: a horse of a brownish orange to light brown color
South American poison toad: a South American toad
South American sea lion: of the southern coast of South America
sow: an adult female hog
sow bug: terrestrial isopod having an oval segmented body (a shape like a sow)
spadefoot: a burrowing toad of the northern hemisphere with a horny spade-like projection on each hind foot
spaniel: any of several breeds of small to medium-sized gun dogs with a long silky coat and long frilled ears
Spanish fly: green beetle of southern Europe
Spanish mackerel: medium-sized mackerel of temperate Atlantic and Gulf of Mexico
Spanish mackerel: any of several large marine food fishes of the genus Scomberomorus
Spanish pointer: a strong slender smooth-haired dog of Spanish origin having a white coat with brown or black patches; scents out and points to game
sparid: spiny-finned food fishes of warm waters having well-developed teeth
sparrow: any of several small dull-colored singing birds feeding on seeds or insects
spat: a young oyster or other bivalve
spawn: the mass of eggs deposited by fish or amphibians or molluscs
spawner: a female fish at spawning time
spearfish: any of several large vigorous pelagic fishes resembling sailfishes but with first dorsal fin much reduced; worldwide but rare
spearnose bat: New World bat with a pointed nose leaf; found from southern United States to Paraguay
Sphecius speciosis: large black or rust-colored wasp that preys on cicadas
sphecoid: any of various solitary wasps
sphenisciform seabird: flightless cold-water seabirds: penguins
Spheniscus demersus: small penguin of South America and southern Africa with a braying call
Sphenodon punctatum: only extant member of the order Rhynchocephalia of large spiny lizard-like diapsid reptiles of coastal islands off New Zealand
Sphyraena barracuda: large (up to 6 ft) greyish-brown barracuda highly regarded as a food and sport fish; may be dangerous to swimmers
Sphyrapicus varius: eastern North American sapsucker having a pale yellow abdomen
Sphyrapicus varius ruber: western North American sapsucker
Sphyrna tiburo: small harmless hammerhead having a spade-shaped head; abundant in bays and estuaries
Sphyrna tudes: fished for the hide and vitamin-rich liver
Sphyrna zygaena: fished for the hides and vitamin-rich liver
spider: predatory arachnid with eight legs, two poison fangs, two feelers, and usually two silk-spinning organs at the back end of the body; they spin silk to make cocoons for eggs or traps for prey
spider crab: any of numerous crabs with very long legs and small triangular bodies
spider mite: web-spinning mite that attacks garden plants and fruit trees
Spilogale putorius: small skunk with a marbled black and white coat; of United States and Mexico
spine: a sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin
Spinus pinus: small finch of North American coniferous forests
spiny dogfish: small bottom-dwelling dogfishes
spiny lizard: any of numerous lizards with overlapping ridged pointed scales; of North America and Central America
spiny puffer: puffers having rigid or erectile spines
SPipistrellus hesperus: of western North America
spirilla: any flagellated aerobic bacteria having a spirally twisted rodlike form
spirillum: spirally twisted elongate rodlike bacteria usually living in stagnant water
Spirillum minus: a bacterium causing ratbite fever
spirochaete: parasitic or free-living bacteria; many pathogenic to humans and other animals
spirogyra: freshwater algae consisting of minute filaments containing spiral chlorophyll bands
Spirula peronii: a small tropical cephalopod of the genus Spirula having prominent eyes and short arms and a many-chambered shell coiled in a flat spiral
spittle insect: small leaping herbivorous insect that lives in a mass of protective froth which it and its larvae secrete
spitz: any of various stocky heavy-coated breeds of dogs native to northern regions having pointed muzzles and erect ears with a curled furry tail
Spizella arborea: finch common in winter in the northern U.S.
Spizella passerina: small North American finch common in urban areas
Spizella pusilla: common North American finch of brushy pasturelands
splint bone: a rudimentary metacarpal or metatarsal bone on either side of the cannon bone in the leg of a horse or related animal
Spodoptera exigua: moth whose larvae are beet armyworms
Spodoptera exigua: moth larva that eats foliage of beets and other vegetables
Spodoptera frugiperda: moth whose larvae are fall armyworms
Spodoptera frugiperda: larva of a migratory American noctuid moth; destroys grasses and small grains
sponge genus: a genus of Porifera
spongefly: hairy-bodied insect whose larvae feed on freshwater sponges
spoonbill: wading birds having a long flat bill with a tip like a spoon
sporozoan: parasitic spore-forming protozoan
sporozoite: one of the minute active bodies into which sporozoans divide in one stage of their life cycle
spouter: a spouting whale
spring cankerworm: variably colored looper; larva of Paleacrita vernata
spring chicken: a young chicken having tender meat
springer: a large spaniel with wavy silky coat usually black or liver and white
springer: a cow about to give birth
squab: an unfledged pigeon
squama: a protective structure resembling a scale
squaretail: sluggish square-tailed fish armored with tough bony scales; of deep warm waters
Squatina squatina: sharks with broad flat bodies and winglike pectoral fins but that swim the way sharks do
squid: widely distributed fast-moving ten-armed cephalopod mollusk having a long tapered body with triangular tail fins
squirrel: a kind of arboreal rodent having a long bushy tail
squirrelfish: very small, brightly colored (especially red) nocturnal fishes of shallow waters or tropical reefs; they make sounds like a squirrel's bark
stable companion: a horse stabled with another or one of several horses owned by the same person
Staffordshire bull terrier: English breed of strong stocky dog having a broad skull and smooth coat
stag: adult male deer
stag beetle: a kind of lamellicorn beetle; the male has branched mandibles resembling antlers
staghorn coral: large branching coral resembling antlers
staghound: a large heavy hound formerly used in hunting stags and other large game; similar to but larger than a foxhound
stalking-horse: a horse behind which a hunter hides while stalking game
standard poodle: a breed or medium-sized poodles
standard schnauzer: a medium-sized schnauzer
staph: spherical Gram-positive parasitic bacteria that tend to form irregular colonies; some cause boils or septicemia or infections
stargazer: heavy-bodied marine bottom-lurkers with eyes on flattened top of the head
starling: gregarious birds native to the Old World
staurikosaur: primitive dinosaur found in Brazil
stayer: a person or other animal having powers of endurance or perseverance
Steatornis caripensis: nocturnal fruit-eating bird of South America that has fatty young yielding an oil that is used instead of butter
steed: (literary) a spirited horse for state of war
steeplechaser: a horse trained to run in steeplechases
Steganopus tricolor: breeds on the northern great plains of Canada
Stegosaur stenops: herbivorous ornithischian dinosaur with a row of bony plates along its back and a spiked tail probably used as a weapon
Stenopelmatus fuscus: large wingless nocturnal grasshopper that burrows in loose soil along the Pacific coast of the United States
Stenopterygius quadrisicissus: an ichthyosaur of the genus Stenopterygius
Stenotomus aculeatus: porgy of southern Atlantic coastal waters of North America
Stenotomus chrysops: found in Atlantic coastal waters of North America from South Carolina to Maine; esteemed as a panfish
stentor: any of several trumpet-shaped ciliate protozoans that are members of the genus Stentor
Stercorarius parasiticus: a variety of jaeger
Sterna hirundo: common tern of Eurasia and America having white black and grey plumage
stick insect: any of various mostly tropical insects having long twiglike bodies
stinger: a sharp organ of offense or defense (as of a wasp or stingray or scorpion) often connected with a poison gland
stingray: large venomous ray with large barbed spines near the base of a thin whiplike tail capable of inflicting severe wounds
stirk: yearling heifer or bullock
Stizostedion vitreum: pike-like freshwater perches
stoat: the ermine in its brown summer coat with black-tipped tail
stocker: a domestic animal (especially a young steer or heifer) kept as stock until fattened or matured and suitable for a breeding establishment
stomatopod: a kind of crustacean
stonewort: any of various submerged aquatic algae of the genus Chara having nodes with whorled filamentlike branches; usually encrusted with calcium carbonate deposits
Storeria occipitamaculata: harmless woodland snake of southeastern United States
stork: large mostly Old World wading birds typically having white-and-black plumage
storm petrel: any of various small petrels having dark plumage with paler underparts
stray: an animal that has strayed (especially a domestic animal)
strep: spherical Gram-positive bacteria occurring in pairs or chains; cause e.g. scarlet fever and tonsillitis
streptobacillus: any of various rod-shaped Gram-negative bacteria
Streptococcus anhemolyticus: a species of bacteria
streptomyces: aerobic bacteria (some of which produce the antibiotic streptomycin)
Streptomyces erythreus: source of the antibiotic erythromycin
Streptomyces griseus: source of the antibiotic streptomycin
Streptomyces scabies: cause of a potato disease characterized by brownish corky tissue
Streptopelia risoria: greyish Old World turtledove with a black band around the neck; often caged
Streptopelia turtur: the common European wild dove noted for its plaintive cooing
Strix aluco: reddish-brown European owl having a round head with black eyes
Strix nebulosa: large dish-faced owl of northern North America and western Eurasia
Strix occidentalis: a large owl of North America found in forests from British Columbia to central Mexico; has dark brown plumage and a heavily spotted chest
Strix varia: large owl of eastern North America having its breast and abdomen streaked with brown
Strizostedion vitreum glaucum: variety inhabiting the Great Lakes
Strombus gigas: a large variety of conch
Struthio camelus: fast-running African flightless bird with two-toed feet; largest living bird
struthiomimus: small light-boned toothless dinosaur resembling an ostrich in size and proportions
Strymon melinus: larvae are pests of various economic plants
stud: adult male horse kept for breeding
stunt: a creature (especially a whale) that has been prevented from attaining full growth
sturgeon: large primitive fishes valued for their flesh and roe; widely distributed in the North Temperate Zone
Sturnella magna: a meadowlark of eastern North America
Sturnella neglecta: a meadowlark of western North America
Sturnus vulgaris: gregarious bird having plumage with dark metallic gloss; builds nests around dwellings and other structures; naturalized worldwide
style: a slender bristlelike or tubular process
stylet: small needlelike appendage; especially the feeding organ of a tardigrade
styracosaur: an unusual ceratopsian dinosaur having many large spikes around the edge of its bony frill and a long nose horn; late Cretaceous
subclass Acnidosporidia: a subclass of Sporozoa
subclass Actinopoda: heliozoans; radiolarians
subclass Amphineura: a class of Gastropoda
subclass Anapsida: oldest known reptiles; turtles and extinct Permian forms
subclass Archaeornithes: primitive reptile-like fossil birds of the Jurassic or early Cretaceous
subclass Archosauria: a large subclass of diapsid reptiles including: crocodiles; alligators; dinosaurs; pterosaurs; plesiosaurs; ichthyosaurs; thecodonts
subclass Branchiopoda: primitive aquatic mainly freshwater crustaceans: fairy shrimps; brine shrimps; tadpole shrimps; can shrimps; water fleas
subclass Cirripedia: barnacles
subclass Cnidosporidia: single-host parasites of lower vertebrates and invertebrates
subclass Copepoda: minute planktonic or parasitic crustaceans
subclass Crossopterygii: fishes having paired fins resembling limbs and regarded as ancestral to amphibians
subclass Diapsida: used in former classifications to include all living reptiles except turtles; superseded by the two subclasses Lepidosauria and Archosauria
subclass Dibranchiata: comprising all living cephalopods except the family Nautilidae: the orders Octopoda (octopuses) and Decapoda (squids and cuttlefish)
subclass Dipnoi: bony fishes of the southern hemisphere that breathe by a modified air bladder as well as gills; sometimes classified as an order of Crossopterygii
subclass Elasmobranchii: sharks; rays; dogfishes; skates
subclass Entomostraca: in some older classifications includes the Branchiopoda and Copepoda and Ostracoda and Cirripedia; no longer in technical use
subclass Euryalida: basket stars
subclass Eutheria: all mammals except monotremes and marsupials
subclass Exopterygota: subclass of insects characterized by gradual and usually incomplete metamorphosis
subclass Holocephali: chimaeras and extinct forms
subclass Infusoria: in some recent classifications, coextensive with the Ciliata: minute organisms found in decomposing infusions of organic matter
subclass Lepidosauria: diapsid reptiles: lizards; snakes; tuataras
subclass Malacostraca: largest subclass of Crustacea including most of the well-known marine, freshwater, and terrestrial crustaceans: crabs; lobsters; shrimps; sow bugs; beach flies
subclass Metatheria: pouched animals
subclass Ophiurida: brittle stars
subclass Opisthobranchia: gastropods having the gills when present posterior to the heart and having no operculum: includes sea slugs; sea butterflies; sea hares
subclass Ostracoda: seed shrimps
subclass Pantotheria: generalized extinct mammals widespread during the Jurassic; commonly conceded to be ancestral to marsupial and placental mammals
subclass Phytomastigina: plantlike flagellates containing chlorophyll; often considered unicellular algae
subclass Prototheria: echidnas; platypus
subclass Rhizopoda: creeping protozoans: amoebas and foraminifers
subclass Synapsida: extinct reptiles of the Permian to Jurassic considered ancestral to mammals
subclass Teleostei: large diverse group of bony fishes; includes most living species
subclass Telosporidia: parasitic sporozoans that form spores containing one or more infective sporozoites
subclass Zoomastigina: in some classifications considered a phylum of the kingdom Protista; holozoic or saprozoic flagellates
subfamily Anserinae: used in some classifications for the swans
subfamily Bassariscidae: in some classifications considered a separate family
subfamily Bovinae: term not used technically; essentially coextensive with genus Bos: cattle; buffalo; and sometimes includes kudu
subfamily Carduelinae: used in some classifications for a subgroup of finches
subfamily Cetoniidae: considered a separate family in some classification systems
subfamily Dorylinae: army ants
subfamily Emberizidae: buntings and some New World sparrows
subfamily Garrulinae: subfamily of the crow family: jays
subfamily Gerbillinae: gerbils
subfamily Hydromyinae: water rats of Australia and New Guinea
subfamily Loriinae: lories
subfamily Lutrinae: subdivision not used in some classifications: otters
subfamily Malaconotinae: an African bush shrikes
subfamily Melinae: subdivision not used in some classifications: badgers
subfamily Melolonthidae: considered a separate family in some classification systems
subfamily Mephitinae: subdivision not used in some classifications: skunks
subfamily Merginae: mergansers and closely related diving birds
subfamily Numididae: guinea fowl and related birds of Africa and Madagascar
subfamily Perdicidae: Old World partridges
subfamily Peristediinae: in some classifications considered a subfamily of Triglidae comprising the armored searobins
subfamily Petauristidae: Old World flying squirrels
subfamily Potoroinae: rat kangaroos
subfamily Pythoninae: Old World boas: pythons; in some classifications considered a separate family from Boidae
subfamily Sterninae: terns
subfamily Sylviinae: alternative classification for the Old World warblers
subfamily Triglinae: in some classifications considered a subfamily of Triglidae comprising searobins having ordinary scales and no barbels (true searobins)
subfamily Turdinae: alternative classification for the thrushes
subgenus Chen: wild goose having white adult plumage
subgenus Pastor: only the rose-colored starlings; in some classifications considered a separate genus
subkingdom Metazoa: multicellular animals having cells differentiated into tissues and organs and usually a digestive cavity and nervous system
subkingdom Parazoa: multicellular organisms having less-specialized cells than in the Metazoa; comprises the single phylum Porifera
suborder Alcyonacea: comprising the soft corals
suborder Anisoptera: dragonflies
suborder Anseres: used in some especially older classifications; coextensive with the family Anatidae
suborder Anthropoidea: monkeys; apes; hominids
suborder Blattaria: cockroaches; in some classifications considered an order
suborder Blennioidea: blennies; butterfishes; gunnels
suborder Brachyura: an order of crustaceans (including true crabs) having a reduced abdomen folded against the ventral surface
suborder Carnosaura: largest carnivorous land animals ever known
suborder Cephalaspida: extinct group of armored fish-like vertebrates; taxonomy is not clear
suborder Ceratopsia: horned dinosaurs
suborder Ceratosaura: primitive saurischian dinosaurs
suborder Charadrii: shorebirds: plovers; sandpipers; avocets; phalaropes; coursers; stone curlews
suborder Clamatores: used in some classification systems; a suborder or superfamily nearly coextensive with suborder Tyranni; Passeriformes having relatively simple vocal organs and little power of song; clamatorial birds
suborder Euronithopoda: widespread group including duck-billed dinosaurs and their early relatives (hadrosaurs, trachodon and iguanodon)
suborder Eurylaimi: broadbills
suborder Gorgoniacea: red corals and sea fans
suborder Heteroptera: true bugs
suborder Heterostraci: extinct group of armored jawless fishes or fish-like vertebrate; taxonomy is not clear
suborder Homoptera: plant lice (aphids); whiteflies; cicadas; leafhoppers; plant hoppers; scale insects and mealybugs; spittle insects
suborder Hystricomorpha: an order of rodents including: porcupines; guinea pigs; chinchillas; etc.
suborder Lacertilia: true lizards; including chameleons and geckos
suborder Lari: gulls; terns; jaegers; skimmers
suborder Lemuroidea: Lemuridae; Lorisidae; Daubentoniidae; Indriidae; used in some classifications instead of Prosimii; in others considered a subdivision of Prosimii
suborder Limicolae: term used in some classifications for migratory shorebirds; coextensive with the Charadrii
suborder Lipotyphla: moles; hedgehogs; true shrews
suborder Maniraptora: advanced theropods including oviraptorids and dromaeosaurs and possibly even modern birds
suborder Manteodea: mantises; in former classifications considered a suborder of Orthoptera
suborder Marginocephalia: includes boneheaded (pachycephalosaurs) and horned (ceratopsian) dinosaurs
suborder Megachiroptera: fruit bats
suborder Megaloptera: in some classifications considered a separate order: alderflies; dobsonflies; snake flies
suborder Menotyphla: elephant shrews; tree shrews
suborder Menurae: lyrebirds and scrubbirds
suborder Microchiroptera: most of the bats in the world; all bats except fruit bats insectivorous bats
suborder Mugiloidea: fishes distinguished by abdominal pelvic fins: families Mugilidae; Atherinidae; Sphyraenidae
suborder Myomorpha: true rats and mice and related rodents
suborder Mysticeti: baleen whales: right whales; rorquals; blue whales; humpbacks
suborder Myxiniformes: hagfishes as distinguished from lampreys
suborder Natantia: shrimp; prawns; etc.
suborder Nematocera: mosquitoes; fungus gnats; crane flies; gnats; sand flies
suborder Nothosauria: a suborder of Sauropterygia
suborder Odontoceti: toothed whales: dolphins; porpoises; sperm whales; beaked whales
suborder Ornithomimida: lightly built medium-size theropods
suborder Otides: terrestrial game birds of the Old World and Australia: bustards
suborder Pachycephalosaurus: boneheaded dinosaurs; late Cretaceous
suborder Passeres: two names for the suborder of typical songbirds
suborder Percoidea: in some classifications nearly or exactly equivalent to the Perciformes which are considered a suborder
suborder Petromyzoniformes: lampreys as distinguished from hagfishes
suborder Pinnipedia: seals; sea lions; walruses
suborder Plesiosauria: any of the plesiosaurs
suborder Prosauropoda: the earliest known dinosaurs
suborder Prosimii: not used in all classifications; in some classifications considered coextensive with the Lemuroidea; in others includes both Lemuroidea and Tarsioidea
suborder Reptantia: lobsters; crabs
suborder Ruminantia: cattle; bison; sheep; goats; antelopes; deer; chevrotains; giraffes; camels
suborder Sauropoda: any of the sauropod dinosaurs
suborder Sauropodomorpha: gigantic herbivorous dinosaurs having huge bodies with long necks and small heads: Prosauropoda and Sauropoda (apatosaurus, diplodocus and titanosaurs)
suborder Sciuromorpha: large more or less primitive rodents: squirrels; marmots; gophers; beavers; etc.
suborder Scombroidea: mackerels; tunas; albacores; bonitos; swordfishes; sailfishes
suborder Scorpaenoidea: mail-cheeked fishes: scorpionfishes; gurnards
suborder Serpentes: snakes
suborder Strepsirhini: in some classifications either coextensive with the Lemuroidea or comprising the true lemurs
suborder Tarsioidea: in some classifications assigned to the suborder Prosimii
suborder Theropoda: carnivorous saurischian dinosaurs with short forelimbs; Jurassic and Cretaceous
suborder Thyreophora: armored dinosaurs: stegosaurs and ankylosaurs
suborder Tyranni: New World flycatchers; antbirds; oven birds; woodhewers
suborder Xenarthra: armadillos; American anteaters; sloths
suborder Zygoptera: damselflies
subphylum Cephalochordata: lancelets
subphylum Pentastomida: tongue worms
subphylum Urochordata: tunicates
subphylum Vertebrata: fishes; amphibians; reptiles; birds; mammals
sucker: mostly North American freshwater fishes with a thick-lipped mouth for feeding by suction; related to carps
sucker: an organ specialized for sucking nourishment or for adhering to objects by suction
sucking pig: an unweaned piglet
suckling: a young mammal that has not been weaned
Sula bassana: very large white gannet with black wing tips
sulfur bacteria: any bacterium of the genus Thiobacillus
sulfur butterfly: any of numerous yellow or orange butterflies
superbug: a strain of bacteria that is resistant to all antibiotics
superclass Agnatha: superclass of eel-shaped chordates lacking jaws and pelvic fins: lampreys; hagfishes; some extinct forms
superclass Chelicerata: spiders; scorpions; horseshoe crabs
superclass Gnathostomata: comprising all vertebrates with upper and lower jaws
superclass Myriapoda: used in some classifications to encompass the millipedes (Diplopoda) and centipedes (Chilopoda); formerly a large taxon including also the Pauropoda and Symphyla; the term Myriapoda now usually used synonymously with Diplopoda and limited to the millipedes
superfamily Aphidoidea: plant lice
superfamily Apoidea: bees
superfamily Coccoidea: scale insects and mealybugs
superfamily Hominoidea: anthropoid apes and human beings
superfamily Lamellicornia: scarabaeid beetles and stag beetles
superfamily Muroidea: a superfamily of rodents essentially equal to the suborder Myomorpha but with the Dipodidae excluded
superfamily Muscoidea: two-winged flies especially the families: Muscidae; Gasterophilidae; Calliphoridae; Tachinidae
superfamily Platyrrhini: New World monkeys: capuchin; douroucouli; howler monkey; saki; spider monkey; squirrel monkey; titi; uakari; woolly monkey; marmoset; tamarin
superfamily Sphecoidea: families Sphecidae and Stizidae
superfamily Tineoidea: clothes moths; carpet moths; leaf miners
superfamily Tyrannidae: New World tyrant flycatchers most numerous in Central America and South America but also in the United States and Canada
superorder Acanthopterygii: teleost fishes having fins with sharp bony rays
superorder Labyrinthodontia: extinct amphibians typically resembling heavy-bodied salamanders or crocodiles and having a solid flattened skull and conical teeth; Devonian through Triassic
superorder Malacopterygii: an extensive group of teleost fishes having fins supported by flexible cartilaginous rays
superorder Ratitae: used in former classifications to include all ratite bird orders
superslasher: large (20-ft) and swift carnivorous dinosaur having an upright slashing claw 15 inches long on each hind foot; early Cretaceous
surf fish: small to medium-sized shallow-water fishes of the Pacific coast of North America
surgeonfish: brightly colored coral-reef fish with knifelike spines at the tail
Suricata suricatta: a meerkat with a thin and elongated tail
Suricata tetradactyla: burrowing diurnal meerkat of southern Africa; often kept as a pet
Surnia ulula: grey-and-white diurnal hawk-like owl of northern parts of the northern hemisphere
survivor: an animal that survives in spite of adversity
Sus scrofa: Old World wild swine having a narrow body and prominent tusks from which most domestic swine come; introduced in United States
Sus scrofa: domestic swine
Sussex spaniel: an English breed with short legs and a golden liver-colored coat
swallow: small long-winged songbird noted for swift graceful flight and the regularity of its migrations
swallow shrike: Australasian and Asiatic bird related to the shrikes and resembling a swallow
swan: stately heavy-bodied aquatic bird with very long neck and usually white plumage as adult
swan's down: down of the swan
sweeper: little-known nocturnal fish of warm shallow seas with an oblong compressed body
sweet-potato whitefly: a variety of whitefly
swift: a small bird that resembles a swallow and is noted for its rapid flight
swimming crab: marine crab with some legs flattened and fringed for swimming
swine: stout-bodied short-legged omnivorous animals
Sydney silky: Australian breed of toy dogs having a silky blue coat
Sylvia communis: greyish-brown Old World warbler with a white throat and underparts
Sylvia curruca: Old World warbler similar to the greater whitethroat but smaller
Sylvilagus aquaticus: a wood rabbit of southeastern United States swamps and lowlands
Sylvilagus floridanus: widely distributed in United States except northwest and far west regions
Sylvilagus palustris: a wood rabbit of marshy coastal areas from North Carolina to Florida
Symbion pandora: only known species of Cycliophora; lives symbiotically attached to a lobster's lip by an adhesive disk and feeding by means of a hairy mouth ring; its complex life cycle includes asexual and sexual phases
Symphalangus syndactylus: large black gibbon of Sumatra having the 2nd and 3rd toes partially united by a web
Synagrops bellus: small marine fish with black mouth and gill cavity
Synanceja verrucosa: venomous tropical marine fish resembling a piece of rock
synapsid: extinct reptile having a single pair of lateral temporal openings in the skull
Synaptomys borealis: of wet alpine and subalpine meadows of Canada and Alaska
Synaptomys cooperi: of low bogs and meadows of northeastern and central United States and southern Canada
Synercus caffer: large often savage buffalo of southern Africa having upward-curving horns; mostly in game reserves
Syngnathus hildebrandi: small (4 inches) fish found off the Florida Gulf Coast
syrinx: the vocal organ of a bird
Syrrhaptes paradoxus: Eurasiatic sandgrouse with a black patch on the belly
tabby: a cat with a grey or tawny coat mottled with black
tachina fly: bristly fly whose larvae live parasitically in caterpillars and other insects; important in control of noxious insects
Tadarida brasiliensis: the common freetail bat of southern United States having short velvety fur; migrates southward for winter
Tadirida femorosacca: small brown bat of California and northern Mexico
tadpole shrimp: a kind of branchiopod crustacean
taenia: tapeworms parasitic in humans which uses the pig as its intermediate host
tail: the posterior part of the body of a vertebrate especially when elongated and extending beyond the trunk or main part of the body
tail feather: feather growing from the tail (uropygium) of a bird
talon: a sharp hooked claw especially on a bird of prey
Tamandua tetradactyla: small toothless anteater with prehensile tail and four-clawed forelimbs; of tropical South America and Central America
Tamias striatus: small striped semiterrestrial eastern American squirrel with cheek pouches
Tamiasciurus douglasi: far western United States counterpart of the red squirrel
Tamiasciurus hudsonicus: of northern United States and Canada
tanager: any of numerous New World woodland birds having brightly colored males
tapir: large inoffensive chiefly nocturnal ungulate of tropical America and southeast Asia having a heavy body and fleshy snout
Tapirus indicus: a tapir found in Malaya and Sumatra
Tapirus terrestris: a tapir found in South America and Central America
tarantula: large hairy tropical spider with fangs that can inflict painful but not highly venomous bites
tardigrade: an arthropod of the division Tardigrada
Taricha granulosa: newt of humid coast from Alaska to southern California
Tarpon atlanticus: large silvery game fish of warm Atlantic coastal waters especially off Florida
tarsier: nocturnal arboreal primate of Indonesia and the Philippines having huge eyes and digits ending in pads to facilitate climbing; the only primate that spurns all plant material as food living entirely on insects and small vertebrates
Tarsius glis: a variety of tarsier
Tarsius syrichta: a variety of tarsier
tattler: any of several long-legged shorebirds having a loud whistling cry
Taurotragus derbianus: large dark striped eland of western equatorial Africa
Taurotragus oryx: dark fawn-colored eland of southern and eastern Africa
Tautoga onitis: large dark-colored food fish of the Atlantic coast of North America
Tautogolabrus adspersus: common in north Atlantic coastal waters of the United States
Tayassu angulatus: dark grey peccary with an indistinct white collar; of semi desert areas of Mexico and southwestern United States
Tayassu pecari: blackish peccary with whitish cheeks; larger than the collared peccary
teal: any of various small short-necked dabbling river ducks of Europe and America
teg: two-year-old sheep
teiid: tropical New World lizard with a long tail and large rectangular scales on the belly and a long tail
teju: large (to 3 feet) blackish yellow-banded South American lizard; raid henhouses; used as food
teleost: a bony fish of the subclass Teleostei
tendrac: small often spiny insectivorous mammal of Madagascar; resembles a hedgehog
Tenrec ecaudatus: prolific animal that feeds chiefly on earthworms
tent caterpillar: the larvae of moths that build and live in communal silken webs in orchard and shade trees
tentacle: any of various elongated tactile or prehensile flexible organs that occur on the head or near the mouth in many animals; used for feeling or grasping or locomotion
tercel: male hawk especially male peregrine or gyrfalcon
teredo: typical shipworm
termite: whitish soft-bodied ant-like social insect that feeds on wood
tern: small slender gull having narrow wings and a forked tail
terrapin: any of various edible North American web-footed turtles living in fresh or brackish water
terrier: any of several usually small short-bodied breeds originally trained to hunt animals living underground
test: a hard outer covering as of some amoebas and sea urchins
testacean: any of various rhizopods of the order Testacea characterized by having a shell
tetra: brightly colored tropical freshwater fishes
tetrahymena: relative of the paramecium; often used in genetics research
Tetrao urogallus: large black Old World grouse
tetrapod: a vertebrate animal having four feet or legs or leglike appendages
Texas horned lizard: of arid and semiarid open country
Texas longhorn: long-horned beef cattle formerly common in southwestern United States
Texas tortoise: close relative to the desert tortoise; may be reclassified as a member of genus Xerobates
Thalarctos maritimus: white bear of Arctic regions
Thalassoma bifasciatum: small Atlantic wrasse the male of which has a brilliant blue head
Thamnophis sauritus: slender yellow-striped North American garter snake; prefers wet places
Thamnophis sirtalis: a garter snake that is widespread in North America
theca: outer sheath of the pupa of certain insects
thecodont: presumably in the common ancestral line to dinosaurs and crocodiles and birds
thermoacidophile: archaebacteria that thrive in strongly acidic environments at high temperatures
Thermobia domestica: lives in warm moist areas e.g. around furnaces
thick skin: skin that is very thick (as an elephant or rhinoceros)
thickhead: Australian and southeastern Asian birds with a melodious whistling call
thin-shelled mussel: mussel with thin fragile shells having only rudimentary hinge teeth
thiobacillus: small rod-shaped bacteria living in sewage or soil and oxidizing sulfur
Thomomys bottae: of valleys and mountain meadows of western United States
Thomomys talpoides: greyish to brown gopher of western and central United States
Thomson's gazelle: East African gazelle; the smallest gazelle
thorax: part of an insect's body that bears the wings and legs
thornbill: any of various South American hummingbirds with a sharp pointed bill
thoroughbred: a racehorse belonging to a breed that originated from a cross between Arabian stallions and English mares
threadfin: mullet-like tropical marine fishes having pectoral fins with long threadlike rays
three year old: a racehorse that is three years old
Threskiornis aethiopica: African ibis venerated by ancient Egyptians
thrip: any of various small to minute sucking insects with narrow feathery wings if any; they feed on plant sap and many are destructive
Thrips tobaci: injurious to onion plants and sometimes tobacco
throat: the part of an animal's body that corresponds to a person's throat
thrush: songbirds characteristically having brownish upper plumage with a spotted breast
Thryothorus ludovicianus: large United States wren with a musical call
Thunnus alalunga: large pelagic tuna the source of most canned tuna; reaches 93 pounds and has long pectoral fins; found worldwide in tropical and temperate waters
Thunnus albacares: may reach 400 pounds; worldwide in tropics
Thunnus thynnus: largest tuna; to 1500 pounds; of mostly temperate seas: feed in polar regions but breed in tropics
Thylacinus cynocephalus: rare doglike carnivorous marsupial of Tasmania having stripes on its back; probably extinct
thysanopter: an insect of the order Thysanoptera
thysanuran insect: primitive wingless insects: bristletail
Tibetan mastiff: very large powerful rough-coated dog native to central Asia
Tibetan terrier: breed of medium-sized terriers bred in Tibet resembling Old English sheepdogs with fluffy curled tails
Tichodroma muriaria: crimson-and-grey songbird that inhabits town walls and mountain cliffs of southern Eurasia and northern Africa
tick: any of two families of small parasitic arachnids with barbed proboscis; feed on blood of warm-blooded animals
tiger beetle: active usually bright-colored beetle that preys on other insects
tiger cat: a cat having a striped coat
tiger cub: a young tiger
tiger moth: medium-sized moth with long richly colored and intricately patterned wings; larvae are called woolly bears
tiglon: offspring of a male tiger and a female lion
tigress: a female tiger
Tilapia nilotica: important food fish of the Nile and other rivers of Africa and Asia Minor
timucu: found in warm waters of western Atlantic
Tinca tinca: freshwater dace-like game fish of Europe and western Asia noted for ability to survive outside water
Tinea pellionella: the larvae live in tubes of its food material fastened with silk that it spins
tineid: small yellowish moths whose larvae feed on wool or fur
tineoid: small dull-colored moth with chewing mouthparts
Tineola bisselliella: moth that forms a web in which it lives
tit: small insectivorous birds
titanosaur: amphibious quadrupedal herbivorous dinosaur with a long thin neck and whiplike tail; of the Cretaceous mostly in the southern hemisphere
titi: small South American monkeys with long beautiful fur and long nonprehensile tail
TMV: the widely studied plant virus that causes tobacco mosaic; it was the first virus discovered (1892)
tody: tiny insectivorous West Indian bird having red-and-green plumage and a long straight bill
Togaviridae: a family of arboviruses carried by arthropods
Tolypeutes tricinctus: South American armadillo with three bands of bony plates
tom: male cat
Tomistoma schlegeli: crocodile of southeast Asia similar to but smaller than the gavial
tonguefish: left-eyed marine flatfish whose tail tapers to a point; of little commercial value
tongueless frog: almost completely aquatic frog native to Africa and Panama and northern South America
tooth: toothlike structure in invertebrates found in the mouth or alimentary canal or on a shell
tooth shell: any of various seashore mollusks having a tapering tubular shell open at each end and a foot pointed like a spade for burrowing
toothed whale: any of several whales having simple conical teeth and feeding on fish etc.
topknot: showy crest or knot of hair or feathers
tortoise: usually herbivorous land turtles having clawed elephant-like limbs; worldwide in arid area except Australia and Antarctica
tortoiseshell: brilliantly colored; larvae feed on nettles
tortricid: any of numerous small moths having lightly fringed wings; larvae are leaf rollers or live in fruits and galls
toucan: brilliantly colored arboreal fruit-eating bird of tropical America having a very large thin-walled beak
toucanet: small toucan
touraco: large brightly crested bird of Africa
towhee: any of numerous long-tailed American finches
toxicognath: either of a pair of poison fangs in the modified front pair of legs of the centipede
Toxostoma rufums: common large songbird of eastern United States having reddish-brown plumage
Toxotes jaculatrix: any of several small freshwater fishes that catch insects by squirting water at them and knocking them into the water; found in Indonesia and Australia
toy Manchester terrier: breed of small Manchester terrier
toy poodle: the breed of very small poodles
toy spaniel: a very small spaniel
toy terrier: a small active dog
toy: any of several breeds of very small dogs kept purely as pets
Trachinotus carolinus: found in coastal waters New England to Brazil except clear waters of West Indies
Trachinotus falcatus: large game fish; found in waters of the West Indies
Trachipterus arcticus: deep-sea ribbonfish
trachodon: large duck-billed dinosaur of the Cretaceous period
Trachurus symmetricus: a California food fish
Trachurus trachurus: large elongated compressed food fish of the Atlantic waters of Europe
Tragelaphus angasi: spiral-horned South African antelope with a fringe of white hairs along back and neck
Tragelaphus buxtoni: shaggy antelope of mountains of Ethiopia
Tragelaphus eurycerus: large forest antelope of central Africa having a reddish-brown coat with white stripes and spiral horns
Tragelaphus imberbis: a smaller variety of kudu
Tragelaphus scriptus: antelope with white markings like a harness and twisted horns
Tragelaphus strepsiceros: a variety of kudu
tragopan: brilliantly colored Asian pheasant having wattles and two fleshy processes on the head
Tragulus Javanicus: chevrotain somewhat larger than the kanchil; found in India and Malaya
Tragulus kanchil: small chevrotain of southeastern Asia
trap-door spider: American spider that constructs a silk-lined nest with a hinged lid
tree creeper: any of numerous South American and Central American birds with a curved bill and stiffened tail feathers that climb and feed like woodpeckers
tree cricket: pale arboreal American cricket noted for loud stridulation
tree frog: arboreal amphibians usually having adhesive disks at the tip of each toe; of southeast Asia and Australia and America
tree frog: any of various Old World arboreal frogs distinguished from true frogs by adhesive suckers on the toes
tree kangaroo: arboreal wallabies of New Guinea and northern Australia having hind and forelegs of similar length
tree shrew: insectivorous arboreal mammal of southeast Asia that resembles a squirrel with large eyes and long sharp snout
tree squirrel: any typical arboreal squirrel
treehopper: small leaping insect that sucks juices of branches and twigs
treponema: spirochete that causes disease in humans (e.g. syphilis and yaws)
Triaenodon obseus: smooth dogfish of Pacific and Indian Oceans and Red Sea having white-tipped dorsal and caudal fins
Trialeurodes vaporariorum: whitefly that inhabits greenhouses
tribe Bovini: term not used technically; essentially coextensive with genus Bos
triceratops: huge ceratopsian dinosaur having three horns and the neck heavily armored with a very solid frill
Trichechus manatus: sirenian mammal of tropical coastal waters of America; the flat tail is rounded
Trichinella spiralis: parasitic nematode occurring in the intestines of pigs and rats and human beings and producing larvae that form cysts in skeletal muscles
trichodesmium: large colonial bacterium common in tropical open-ocean waters; important in carbon and nitrogen fixation
Trichoglossus moluccanus: a kind of lorikeet
trichomonad: cause of trichomoniasis in women and cattle and birds
Trichophaga tapetzella: larvae feed on carpets and other woolens
trichopteran: caddis fly
Trichosurus vulpecula: bushy-tailed phalanger
Trichys lipura: porcupine of Borneo and Sumatra having short spines and a long tail
Tridacna gigas: a large clam inhabiting reefs in the southern Pacific and weighing up to 500 pounds
triggerfish: any of numerous compressed deep-bodied tropical fishes with sandpapery skin and erectile spines in the first dorsal fin
Trigla lucerna: a kind of gurnard
trilobite: an extinct arthropod that was abundant in Paleozoic times; had an exoskeleton divided into three parts
Trimorphodon lambda: of desert regions of southwestern North America
Trinectes maculatus: useless as food; in coastal streams from Maine to Texas and Panama
Tringa flavipes: a variety of yellowlegs
Tringa melanoleuca: a variety of yellowlegs
Tringa nebularia: large European sandpiper with greenish legs
Tringa totanus: a common Old World wading bird with long red legs
Trinil man: fossil remains found in Java; formerly called Pithecanthropus erectus
Trionyx muticus: river turtle of Mississippi basin; prefers running water
Trionyx spiniferus: river turtle of western United States with a warty shell; prefers quiet water
tripletail: large food fish of warm waters worldwide having long anal and dorsal fins that with a caudal fin suggest a three-lobed tail
triton: tropical marine gastropods having beautifully colored spiral shells
Triturus vulgaris: small semiaquatic salamander
Trogium pulsatorium: a variety of booklouse
Troglodytes aedon: common American wren that nests around houses
Troglodytes troglodytes: small wren of coniferous forests of northern hemisphere
trogon: forest bird of warm regions of the New World having brilliant lustrous plumage and long tails
trombiculid: mite that as nymph and adult feeds on early stages of small arthropods but whose larvae are parasitic on terrestrial vertebrates
trombidiid: mite that in all stages feeds on other arthropods
trophoblast: the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall
trophozoite: a sporozoan in the active feeding stage of its life cycle
tropical prawn: edible tropical and warm-water prawn
Tropidoclonion lineatum: secretive snake of city dumps and parks as well as prairies and open woods; feeds on earthworms; of central United States
trotter: foot of a pig or sheep especially one used as food
trotter: a horse trained to trot; especially a horse trained for harness racing
trout: any of various game and food fishes of cool fresh waters mostly smaller than typical salmons
true bug: any of various insects of the order Hemiptera and especially of the suborder Heteroptera
true lobster: large edible marine crustaceans having large pincers on the first pair of legs
true marmoset: a marmoset
true toad: tailless amphibian similar to a frog but more terrestrial and having drier warty skin
true vampire bat: any of various tropical American bats of the family Desmodontidae that bite mammals and birds to feed on their blood
trumpeter: large gregarious crane-like bird of the forests of South America having glossy black plumage and a loud prolonged cry; easily domesticated
tube foot: tentacular tubular process of most echinoderms (starfish and sea urchins and holothurians) having a sucker at the end and used for e.g. locomotion and respiration
tuft: a bunch of feathers or hair
tumblebug: any of various dung beetles
tumor virus: a cell-free filtrate held to be a virus responsible for a specific neoplasm
tuna: any very large marine food and game fish of the genus Thunnus; related to mackerel; chiefly of warm waters
Tunga penetrans: small tropical flea; the fertile female burrows under the skin of the host including humans
tunicate: primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva
Turdus greyi: robin of Mexico and Central America
Turdus iliacus: small European thrush having reddish flanks
Turdus migratorius: large American thrush having a rust-red breast and abdomen
Turdus philomelos: common Old World thrush noted for its song
Turdus pilaris: medium-sized Eurasian thrush seen chiefly in winter
Turdus torquatus: European thrush common in rocky areas; the male has blackish plumage with a white band around the neck
Turdus viscivorus: large European thrush that feeds on mistletoe berries
Turnix sylvatica: a variety of button quail having stripes
turnstone: migratory shorebirds of the plover family that turn over stones in searching for food
turtle: any of various aquatic and land reptiles having a bony shell and flipper-like limbs for swimming
turtledove: any of several Old World wild doves
tusk: a long pointed tooth specialized for fighting or digging; especially in an elephant or walrus or hog
tusker: any mammal with prominent tusks (especially an elephant or wild boar)
tussock caterpillar: larva of a tussock moth
twitterer: a bird that twitters
two year old: a racehorse that is two years old
Tylenchus tritici: small roundworm parasitic on wheat
Tympanuchus cupido: the most common variety of prairie chicken
Tympanuchus cupido cupido: extinct prairie chicken
Tympanuchus pallidicinctus: a smaller prairie chicken of western Texas
typhoid bacteriophage: a bacteriophage specific for the bacterium Salmonella typhi
typical jerboa: small nocturnal jumping rodent with long hind legs; of arid parts of Asia and northern Africa
tyrannid: a passerine bird of the suborder Tyranni
Tyrannosaurus rex: large carnivorous bipedal dinosaur having enormous teeth with knifelike serrations; may have been a scavenger rather than an active predator; later Cretaceous period in North America
Tyrannus domenicensis domenicensis: a kingbird that breeds in the southeastern United States and winters in tropical America; similar to but larger than the eastern kingbird
Tyrannus tyrannus: large American flycatcher
Tyrannus vociferans: a kingbird seen in the southwestern United States; largely grey with a yellow abdomen
Tyto alba: mottled buff and white owl often inhabiting barns and other structures; important in rodent control
uakari: medium-sized tree-dwelling monkey of the Amazon basin; only New World monkey with a short tail
Uma notata: with long pointed scales around toes; of deserts of United States and Mexico
umbilical vesicle: membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional
Umbrina roncador: a fish of the Pacific coast of North America
undercoat: thick soft fur lying beneath the longer and coarser guard hair
underpart: a part lying on the lower side or underneath an animal's body
underwing: moth having dull forewings and brightly colored hind wings
Unguiculata: in former classifications a major division of Mammalia comprising mammals with nails or claws; distinguished from hoofed mammals and cetaceans
unguiculate: a mammal having nails or claws
Ungulata: in former classifications a major division of Mammalia comprising all hoofed mammals; now divided into the orders Perissodactyla (odd-toed ungulates) and Artiodactyla (even-toed ungulates)
Uria aalge: the most frequent variety of murre
Uria lomvia: a variety of murre
urochord: a notochord of a larval tunicate typically confined to the caudal region
Urocyon cinereoargenteus: dark grey American fox; from Central America through southern United States
Uropsilus soricipes: shrew mole of eastern Asia
uropygium: posterior part of a bird's body from which the tail feathers grow
Urosaurus ornatus: a climbing lizard of western United States and northern Mexico
Ursus arctos: large ferocious bear of Eurasia
Ursus arctos horribilis: powerful brownish-yellow bear of the uplands of western North America
Ursus arctos middendorffi: brown bear of coastal Alaska and British Columbia
Ursus arctos syriacus: yellowish-grey Syrian brown bear
Uta stansburiana: one of the most abundant lizards in the arid western United States
valve: one of the paired hinged shells of certain molluscs and of brachiopods
valve: the entire one-piece shell of a snail and certain other molluscs
vane: the flattened weblike part of a feather consisting of a series of barbs on either side of the shaft
Vanessa atalanta: of temperate Europe and Asia; having black wings with red and white markings
Vanessa virginiensis: American butterfly having dark brown wings with white and golden orange spots
Varanus komodoensis: the largest lizard in the world (10 feet); found on Indonesian islands
Varanus niloticus: destroys crocodile eggs
varicella zoster virus: the member of the herpes virus family that is responsible for chickenpox
variola major: a type of smallpox virus that has a fatality rate of up to 25 percent
variola minor: a type of smallpox virus that has a fatality rate of about 1 percent
varment: any usually predatory wild animal considered undesirable; e.g., coyote
vector: (genetics) a virus or other agent that is used to deliver DNA to a cell
velociraptor: small active carnivore that probably fed on protoceratops; possibly related more closely to birds than to other dinosaurs
velvet ant: a solitary wasp of the family Mutillidae; the body has a coat of brightly colored velvety hair and the females are wingless
venomous lizard: any of two or three large heavy-bodied lizards; only known venomous lizards
vent: external opening of urinary or genital system of a lower vertebrate
Venus's flower basket: a deep-water marine sponge having a cylindrical skeleton of intricate glassy latticework; found in the waters of the East Indies and the eastern coast of Asia
Venus's girdle: ctenophore having a ribbon-shaped iridescent gelatinous body
vermin: any of various small animals or insects that are pests; e.g. cockroaches or rats
vesiculovirus: an animal virus that causes vesicular stomatitis
Vespa crabro: European hornet introduced into the United States
vespertilian bat: a variety of carnivorous bat
Vespertilio murinus: common Eurasian bat with white-tipped hairs in its coat
vespid: mostly social nest-building wasps
Vespula maculata: North American hornet
Vespula maculifrons: small yellow-marked social wasp commonly nesting in the ground
Vespula vulgaris: a variety of vespid wasp
Vibrio comma: comma-shaped bacteria that cause Asiatic cholera
Vibrio fetus: bacteria that cause abortion in sheep
vibrio: curved rodlike motile bacterium
Vicugna vicugna: small wild cud-chewing Andean animal similar to the guanaco but smaller; valued for its fleecy undercoat
villus: a minute hairlike projection on mucous membrane
vine snake: slender arboreal snake found from southern Arizona to Bolivia
vinegar fly: flies whose larvae feed on pickles and imperfectly sealed preserves
viper: venomous Old World snakes characterized by hollow venom-conducting fangs in the upper jaw
Vipera aspis: of southern Europe; similar to but smaller than the adder
Vipera berus: small terrestrial viper common in northern Eurasia
vireo: any of various small insectivorous American birds chiefly olive-grey in color
Vireo olivaceous: of northern North America having red irises and an olive-grey body with white underparts
Vireo solitarius: of eastern North America having a bluish-grey head and mostly green body
Vireo solitarius solitarius: common vireo of northeastern North America with bluish slaty-grey head
Virginia oyster: common edible oyster of Atlantic coast of North America
virion: (virology) a complete viral particle; nucleic acid and capsid (and a lipid envelope in some viruses)
viroid: the smallest of viruses; a plant virus with its RNA arranged in a circular chromosome without a protein coat
virus: (virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein
vitellus: nutritive material of an ovum stored for the nutrition of an embryo (especially the yellow mass of a bird or reptile egg)
Viverra zibetha: common civet of India and southeast Asia
Viverricula malaccensis: a common civet of southeast Asia
viverrine: small cat-like predatory mammals of warmer parts of the Old World
vixen: a female fox
vorticella: any of various protozoa having a transparent goblet-shaped body with a retractile stalk
Vulpes fulva: New World fox; often considered the same species as the Old World fox
Vulpes macrotis: small grey fox of southwestern United States; may be a subspecies of Vulpes velox
Vulpes velox: small grey fox of the plains of western North America
Vulpes vulpes: the common Old World fox; having reddish-brown fur; commonly considered a single circumpolar species
Vultur gryphus: large vulture of the high Andes having black plumage and white neck ruff
vulture: any of various large diurnal birds of prey having naked heads and weak claws and feeding chiefly on carrion
wader: any of many long-legged birds that wade in water in search of food
wagtail: Old World bird having a very long tail that jerks up and down as it walks
Walker foxhound: an American breed of foxhound
War Admiral: thoroughbred that won the triple crown in 1937
warble: a lumpy abscess under the hide of domestic mammals caused by larvae of a botfly or warble fly
warble fly: hairy bee-like fly whose larvae produce lumpy abscesses (warbles) under the skin of cattle
warbler: a small active songbird
warhorse: horse used in war
warragal: Australian wild horse
warthog: African wild swine with warty protuberances on the face and large protruding tusks
wasp: social or solitary hymenopterans typically having a slender body with the abdomen attached by a narrow stalk and having a formidable sting
water beetle: any of numerous aquatic beetles usually having a smooth oval body and flattened hind legs for swimming
water bird: freshwater aquatic bird
water bug: a true bug: large aquatic bug adapted to living in or on the surface of water
water dog: a dog accustomed to water and usually trained to retrieve waterfowl
water moccasin: any of numerous North American water snakes inhabiting fresh waters
water rat: any of various amphibious rats
water scorpion: long-legged aquatic insect having the front legs fitted for seizing and holding prey and the abdomen extended by a long breathing tube
water shrew: any of several small semiaquatic shrews usually living near swift-flowing streams
water snake: any of various mostly harmless snakes that live in or near water
water spaniel: any dog of two large curly-coated breeds used for hunting waterfowl
water thrush: brownish North American warbler found near streams
water vascular system: system of fluid-filled tubes used by echinoderms in locomotion and feeding and respiration
waterbuck: any of several large African antelopes of the genus Kobus having curved ridged horns and frequenting e.g. swamps and rivers
waterdog: any of several large aquatic salamanders
wax insect: any of various insects that secrete a waxy substance
waxwing: brown velvety-plumaged songbirds of the northern hemisphere having crested heads and red waxy wing tips
weasel: small carnivorous mammal with short legs and elongated body and neck
weaver: finch-like African and Asian colonial birds noted for their elaborately woven nests
web: membrane connecting the toes of some aquatic birds and mammals
web spinner: any of a small order of slender typically tropical insects that nest in colonies in silken tunnels that they spin
web-spinning mite: a mite that spins a web
web-toed salamander: any of several salamanders with webbed toes and very long extensile tongues; excellent climbers that move with ease over smooth rock surfaces
webbed foot: a bird's foot with folds of skin between the toes
webfoot: a foot having the toes connected by folds of skin
webworm: several gregarious moth larvae that spin webs over foliage on which they feed
webworm moth: a variety of moth that spins a web in which it lives
weevil: any of several families of mostly small beetles that feed on plants and plant products; especially snout beetles and seed beetles
Weimaraner: large breed of hound having a smooth greyish coat; originated in Germany
Welsh Black: a breed of dual-purpose cattle developed in Wales
Welsh corgi: either of two Welsh breeds of long-bodied short-legged dogs with erect ears and a fox-like head
Welsh pony: breed of small ponies originally from Wales
Welsh springer spaniel: a red-and-white breed slightly smaller than the English springer spaniel
Welsh terrier: wire-haired terrier resembling Airedales but smaller; developed in Wales for hunting
West Highland white terrier: small white long-coated terrier developed in Scotland
West Nile encephalitis virus: the flavivirus that causes West Nile encephalitis
Western box turtle: primarily a prairie turtle of western United States and northern Mexico
Western diamondback rattlesnake: largest and most dangerous North American snake; of southwestern United States and Mexico
Western rattlesnake: widely distributed between the Mississippi and the Rockies
Western ribbon snake: yellow- or reddish-striped snake of temperate woodlands and grasslands to tropics
wether: male sheep especially a castrated one
whale: any of the larger cetacean mammals having a streamlined body and breathing through a blowhole on the head
whale louse: amphipod crustacean parasitic on cetaceans
wharf rat: brown rat that infests wharves
wheatear: small songbird of northern America and Eurasia having a distinctive white rump
wheel horse: a draft horse harnessed behind others and nearest the wheels of a vehicle
whelk: large carnivorous marine gastropods of coastal waters and intertidal regions having a strong snail-like shell
whidah: mostly black African weaverbird
whiff: a lefteye flounder found in coastal waters from New England to Brazil
whip scorpion: nonvenomous arachnid that resembles a scorpion and that has a long thin tail without a stinger
whip snake: any of several small fast-moving snakes with long whiplike tails
whippet: small slender dog of greyhound type developed in England
whiptail: any of numerous very agile and alert New World lizards
Whirlaway: thoroughbred that won the triple crown in 1941
whirligig beetle: aquatic beetle that circles rapidly on the water surface
white elephant: albinic Indian elephant; rare and sometimes venerated in east Asia
whitebait: the edible young of especially herrings and sprats and smelts
whitefish: silvery herring-like freshwater food fish of cold lakes of the northern hemisphere
whitefly: minute insect that feeds on plant juices; related to scale insects
whiting: a small fish of the genus Sillago; excellent food fish
whiting: any of several food fishes of North American coastal waters
wiggler: larva of a mosquito
wild ass: any of several equine mammals of Asia and northeast Africa
wild dog: any of various undomesticated mammals of the family Canidae that are thought to resemble domestic dogs as distinguished from jackals or wolves
wild duck: an undomesticated duck (especially a mallard)
wild goat: undomesticated goat
wild horse: undomesticated or feral domestic horse
wild sheep: undomesticated sheep
wildcat: any small or medium-sized cat resembling the domestic cat and living in the wild
Wilson's blackcap: yellow wood warbler with a black crown
wing: a movable organ for flying (one of a pair)
wire-haired fox terrier: a fox terrier with wiry hair
wirehair: a terrier with wiry hair
wireworm: wormlike larva of various elaterid beetles; feeds on roots of many crop plants
wishbone: the furcula of a domestic fowl
withers: the highest part of the back at the base of the neck of various animals especially draft animals
wolf: any of various predatory carnivorous canine mammals of North America and Eurasia that usually hunt in packs
wolf cub: a young wolf
wolfhound: the largest breed of dogs; formerly used to hunt wolves
wombat: burrowing herbivorous Australian marsupials about the size of a badger
wood drake: male wood duck
wood hoopoe: tropical African bird having metallic blackish plumage but no crest
wood mouse: any of various New World woodland mice
wood rat: any of various small short-tailed rodents of the northern hemisphere having soft fur grey above and white below with furred tails and large ears; some are hosts for Ixodes pacificus and Ixodes scapularis (Lyme disease ticks)
woodcock: game bird of the sandpiper family that resembles a snipe
woodworm: a larva of a woodborer
woolly adelgid: an insect that feeds on hemlocks; its egg sacs are small fuzzy white balls like artificial snow on a Christmas tree
woolly aphid: secretes a waxy substance like a mass of fine curly white cotton or woolly threads
woolly bear moth: larva of moth of the family Arctiidae
woolly bear: caterpillar of numerous moths characterized by a dense coat of woolly hairs; feed on plants and some are destructive pests
woolly monkey: large monkeys with dark skin and woolly fur of the Amazon and Orinoco basins
work animal: an animal trained for and used for heavy labor
worker: sterile member of a colony of social insects that forages for food and cares for the larvae
worker bee: sterile bee specialized to collect food and maintain the hive
workhorse: a horse used for plowing and hauling and other heavy labor
working dog: any of several breeds of usually large powerful dogs bred to work as draft animals and guard and guide dogs
worm: any of numerous relatively small elongated soft-bodied animals especially of the phyla Annelida and Chaetognatha and Nematoda and Nemertea and Platyhelminthes; also many insect larvae
worm family: a family of worms
worm fish: poorly known family of small tropical shallow-water fishes related to gobies
worm genus: a genus of worms
worm lizard: a lizard of the genus Amphisbaena; harmless wormlike limbless lizard of warm or tropical regions having concealed eyes and ears and a short blunt tail
wrack: dried seaweed especially that cast ashore
wrasse: chiefly tropical marine fishes with fleshy lips and powerful teeth; usually brightly colored
wren warbler: small Asiatic and African bird; constructs nests like those of tailorbirds
wryneck: Old World woodpecker with a peculiar habit of twisting the neck
WTV: a tumor virus transmitted by leafhoppers
xanthomonad: bacteria producing yellow non-water-soluble pigments; some pathogenic for plants
Xenicus gilviventris: short-tailed bird resembling a wren
Xenorhyncus asiaticus: large mostly white Australian stork
Xestobium rufovillosum: bores through wood making a ticking sound popularly thought to presage death
Xiphias gladius: large toothless marine food fish with a long swordlike upper jaw; not completely cold-blooded i.e. they are able to warm their brains and eyes: worldwide in warm waters but feed on cold ocean floor coming to surface at night
Xiphosurus polyphemus: large marine arthropod of the Atlantic coast of North America having a domed carapace that is shaped like a horseshoe and a stiff pointed tail; a living fossil related to the wood louse
Xyphophorus helleri: freshwater fish of Central America having a long swordlike tail; popular aquarium fish
yearling: an animal in its second year
yearling: a racehorse considered one year old until the second Jan. 1 following its birth
yellow-green algae: any alga of the division Chrysophyta with its chlorophyll masked by yellow pigment
yellowlegs: either of two North American shorebird with yellow legs
yellowthroat: small olive-colored American warblers with yellow breast and throat
Yersinia pestis: a bacillus bacterium that causes the plague; aerosolized bacteria can be used as a bioweapon
yolk sac: membranous structure enclosing the yolk of eggs in birds, reptiles, marsupials, and some fishes; circulates nutrients to the developing embryo
Yorkshire terrier: very small breed having a long glossy coat of bluish-grey and tan
Yosemite toad: of high Sierra Nevada meadows and forest borders
young bird: a bird that is still young
young fish: a fish that is young
young mammal: any immature mammal
Zalophus californianus: often trained as a show animal
Zapus hudsonius: widely distributed in northeastern and central United States and Canada
zebra: any of several fleet black-and-white striped African equines
zebu: domesticated ox having a humped back and long horns and a large dewlap; used chiefly as a draft animal in India and east Asia
Zenaidura macroura: wild dove of the United States having a mournful call
Zeus faber: European dory
Zoarces viviparus: an eelpout of northern Europe that is viviparous
Zonotrichia albicollis: common North American finch with a white patch on the throat and black-and-white striped crown
Zonotrichia leucophrys: finch with black-and-white striped crown
zooflagellate: flagellate protozoan lacking photosynthesis and other plant-like characteristics
zooid: one of the distinct individuals forming a colonial animal such as a bryozoan or hydrozoan
zoophyte: any of various invertebrate animals resembling a plant such as a sea anemone or coral or sponge
zooplankton: animal constituent of plankton; mainly small crustaceans and fish larvae
zygodactyl foot: a bird's foot having the first and fourth toes of each foot directed backward and the second and third forward