Definition of Paleocene in US English:



  • 1Relating to or denoting the earliest epoch of the Tertiary period, between the Cretaceous period and the Eocene epoch.

    The Paleocene epoch lasted from 65 million 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) that occurred at the end of the Cretaceous period (see Cretaceous–Tertiary boundary)

    • ‘Initiation of a cold, upwelling current off the west coast of South America dates back to latest Cretaceous to earliest Palaeocene times.’
    • ‘Echinoids are among the most conspicuous and diverse constituents of the Upper Cretaceous and Paleocene marine invertebrate fauna of Argentina.’
    • ‘Both polar and Tethyan dispersal routes have been well documented for Cretaceous and Paleocene decapod crustaceans.’
    • ‘Terrestrial deposits contain fossils ranging from Paleocene leaf imprints to Cretaceous dinosaur remains.’
    • ‘This trend is evident at a coarse scale in a comparison of the combined rarefaction curves for sites from the uppermost 15 m of the Cretaceous against all Paleocene sites.’
    1. 1.1as noun the Paleocene The Paleocene epoch or the system of rocks deposited during it.


Late 19th century: from paleo- + Greek kainos ‘new’.