Geologic Time Scale: Eocene Epoch
(56 to 33.9 million years ago)
The Eocene is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name Eocene comes from the Ancient Greek meaning “dawn” and “new/recent” and refers to the “dawn” of modern (“new”) fauna that appeared during the epoch.
The Eocene is known for containing the warmest period during the Cenozoic, as well as the decline into an icehouse climate and rapid expansion of the Antartic ice sheet. The Eocene bears witness to the introduction of the first flying mammals-bats and marine mammals-whales. Many modern plant and bird orders first appear.