Eocene

詳細解釋：

E.o.cene

adj.（形容詞）
Of, relating to, or designating the geologic time, rock series, sedimentary deposits, and fossils of the second oldest of the five major epochs of the Tertiary Period, extending from the end of the Paleocene to the beginning of the Oligocene, and characterized by the rise of mammals.See table at geologic time
始新世的：關於或標明第三紀的五個世中第二世的地質時代、岩系段，沉積礦床和化石的，該世由古新世末期到漸新世初期，以哺乳動物的繁盛為特徵參見 geologic time
n.（名詞）
The Eocene Epoch.
始新世
The deposits of the Eocene Epoch.
始新世礦床