Paleogene

American  

[pey-lee-uh-jeen, pal-ee-] / ˈpeɪ li əˌdʒin, ˈpæl i- /

adjective

1. noting or pertaining to the earlier part of the Cenozoic Era, in the system adopted by some geologists, occurring from 65 to 25 million years ago and including the Oligocene, Eocene, and Paleocene epochs: corresponds to the earlier part of the Tertiary Period in the system generally used in the U.S.

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noun

1. the Paleogene Period or System.

Paleogene Scientific  

/ pā′lē-ə-jēn′ /

1. The oldest of two subdivisions of the Tertiary Period, including the Paleocene, Eocene, and Oligocene Epochs.

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Etymology

Origin of Paleogene

1880–85; < German Paläogen, equivalent to paläo- paleo- + -gen (< Greek genésthai to be born); -gen

Example Sentences

High-precision dating determined that fossils from these rocks are between 66.4 and 66 million years old, placing them right at the boundary between the Cretaceous and Paleogene periods, when the global extinction event occurred.

From Science Daily • Oct. 26, 2025

The apocalyptic spectacle marked the end of the Cretaceous period, during which terrestrial dinosaurs had dominated the landscape, and the beginning of a new Paleogene era.

From Science Magazine • Oct. 22, 2021

To stratigraphers, the iridium forms the “golden spike” between the Cretaceous and Paleogene periods.

From The Guardian • May 30, 2019

In that moment, the Cretaceous period ended and the Paleogene period began.

From The New Yorker • Mar. 29, 2019

For example, as already noted, the boundary between the Cretaceous and the Paleogene coincides exactly with the extinction of the dinosaurs.

From Textbooks • Jan. 1, 2015