- noting or pertaining to an epoch of the Tertiary Period, occurring from 40 to 25 million years ago.
- the Oligocene Epoch or Series.
Origin of Oligocene
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for oligocene
The next epoch, the Oligocene, was similar but somewhat cooler.The New Stone Age in Northern Europe
John M. Tyler
In the Oligocene we find primitive squirrels, beavers, rabbits, and mice.The Story of Evolution
No noteworthy fossil spiders are known; the best-preserved are in amber of Oligocene age.
Heteromyids are known from the Chadron formation, of early Oligocene age, in which a single tooth was found.Speciation in the Kangaroo Rat, Dipodomys ordii
Henry W. Setzer
Specially interesting in the Eocene and Oligocene are the mammalian remains.The Geological Story of the Isle of Wight
J. Cecil Hughes
- of, denoting, or formed in the third epoch of the Tertiary period, which lasted for 10 000 000 years
- the Oligocene the Oligocene epoch or rock series
C19: oligo- + -cene
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for oligocene
Online Etymology Dictionary, © 2010 Douglas Harper
- The third epoch of the Tertiary Period, from about 37 to 24 million years ago. During this time there was an increase in volcanic activity, and Australia and South America separated from Antarctica. The climate started to cool and a glacier started to form in Antarctica. Modern mammalian groups continued to develop, and the first cats, dogs, horses, and related mammals appeared. Artiodactyls (even-toed ungulates) took over from the perissodactyls (uneven-toed ungulates) as the dominant medium-sized herbivores. Many types of grass also first appeared at this time. See Chart at geologic time.
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