paleocene

Noun
  1. From 63 million to 58 million years ago;
    Appearance of birds and earliest mammals (synset 115150952)
    is an instance of: epoch - a unit of geological time that is a subdivision of a period and is itself divided into ages
    is a part of: tertiary, tertiary period - from 63 million to 2 million years ago
    same as: paleocene epoch

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