Word

Age of Mammals, n.

approximately the last 63 million years
<noun.time>

Age of Mammals Cenozoic Cenozoic era

semantic pointers

part holonym

Phanerozoic, Phanerozoic eon, Phanerozoic aeon

instance hypernym

era, geological era

part meronym

Quaternary, Quaternary period, Age of Man Tertiary, Tertiary period