Learn how to say Paleocene correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word Palaeocene:
relating to or denoting the earliest epoch of the Tertiary period, between the Cretaceous period and the Eocene epoch.
(as noun the Palaeocene) the Palaeocene epoch or the system of rocks deposited during it.
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)
late 19th century: from palaeo- + Greek kainos ‘new’