English Oligocene Cited by user Kent G. Budge on 01 Aug 2021 The Oligocene is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present .
English Eocene Cited by user Kent G. Budge on 21 Jun 2021 The Eocene Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya).