Paleocene

Pa·le·o·cene  (pl--sn)

adj.

Of or belonging to the geologic time, rock series, or sedimentary deposits of the first epoch of the Tertiary Period, marked by the appearance of placental mammals and continental collisions leading to the formation of the Rocky Mountains and the Himalayas. See Table at geologic time.

n.

The Paleocene Epoch or its system of deposits.

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Paleocene  (pl--sn)

The earliest epoch of the Tertiary Period, from about 65 to 58 million years ago. During this time, the Rocky Mountains formed and sea levels dropped, exposing dry land in North America, Australia, and Africa. Many new types of small mammals evolved and filled the niches left empty after the extinctions that ended the Cretaceous Period. Soft-bodied squid replaced the ammonites as the dominant form of mollusk. See Chart at geologic time.

Thesaurus

Noun

1.

Paleocene - from 63 million to 58 million years ago; appearance of birds and earliest mammals Paleocene epoch Tertiary, Tertiary period - from 63 million to 2 million years ago