Eocene - 55 to about 35 million years ago, an epoch of the Tertiary Period. Also the rocks formed during this time.
from 58 million to 40 million years ago; presence of modern mammals
second epoch of the Tertiary period, lasting for 20 million years during which hooved mammals first appeared; from Greek eos 'dawn, early' + kainos 'recent'.
An epoch of the lower Tertiary period, spanning the time between 55.5 and 33.7 million years ago. Its name is from the Greek words "eos" (dawn) and "ceno" (new).
Geological epoch 54 – 38 million years ago.
The second of the five Geologic Epochs of the Tertiary Period. It extends from the end of the Paleocene Epoch (about 55 million years ago) to the beginning of the Oligocene Epoch (about 37 million years ago).
The second Epoch of the Cenozoic, 54.8-33.7 Mya. The Early Eocene (34.8-49 Mya) is the Ypressian Age. The Middle Eocene (49.0-37.0 Mya) includes the Lutetian and Bartonian Ages. The Late Eocene (37.0-33.7 Mya) is the Priabonian Age.
The earliest of the three divisions of the Tertiary epoch of geologists. Rocks of this age contain a small proportion of shells identical with species now living. 65
the name given to the period of earth's history between 57 and 32 million years ago.
the second epoch of the Tertiary period, after the Paleocene and before the Oligocene, during which the ancestors of many modern mammals appeared; the rocks formed during this epoch. [AHDOS
The Eocene epoch (55.8 ± 0.2 - 33.9 ± 0.1 Ma) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. The Eocene spans the time from the end of the Paleocene epoch to the beginning of the Oligocene epoch. The start of the Eocene is marked by the emergence of the first modern mammals.