Paleocene - 65 to about 55 million years ago, the oldest epoch of the Tertiary Period. Also the rocks formed during this time.
An epoch of the Tertiary period, Cenozoic era; ca. 65 - 54 million years ago.
The first of the five Geologic Epochs of the Tertiary Period. It extends from the end of the Mesozoic Era (about 65 million years ago) to the beginning of the Eocene Epoch (about 55 million years ago).