Britannica
Sources used in this answer
When did the Eocene Epoch begin and end?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Cenozoic Era
Principal Cenozoic faunal migration routes and barriers.
The Eocene Epoch began 56 million years ago and ended 33.9 million years ago. It represents the second of three major divisions within the Paleogene Period, occurring between the Paleocene Epoch and the Oligocene Epoch.12