Palaeocene
/ˈpælɪəʊsiːn/( <美> Paleocene)
adjective
1- Geology of, relating to, or denoting the earliest epoch of the Tertiary period, between the Cretaceous period and the Eocene epoch【地质】（与）古新世（有关）的（第三纪早期, 在白垩纪和始新世之间）。
1.1
- as noun the Palaeocene the Palaeocene epoch or the system of rocks deposited during it古新世; 古新统。
The Paleocene epoch lasted from 65.0 to 56.5 million years ago. It was a time of sudden diversification among the mammals, probably as a result of the mass extinctions (notably of the dinosaurs) which occurred at the end of the Cretaceous period （see CRETACEOUS-TERTIARY BOUNDARY）.
词源
late 19th cent.: from PALAEO- (relating to prehistoric times) + Greek kainos 'new'.