Eocene

Second epoch of the Paleogene Period

The Eocene (IPA: EE-ə-seen, EE-oh-) is a geological epoch that began about 56 million years ago (Ma). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The end point of the Eocene is the Eocene-Oligocene transition (EOT), between 33.9 and 33.4 Ma.

From Wikipedia, under CC BY-SA. More on occurri.