1. oligocene - Noun
2. oligocene - Adjective
3. Oligocene - Proper noun
Of, pertaining to, or designating, certain strata which occupy an intermediate position between the Eocene and Miocene periods.
The Oligocene period. See the Chart of Geology.
Source: Webster's dictionaryA Cephalogale-like species gave rise to the genus Ursavus during the early Oligocene (30–28 Mya); this genus proliferated into many species in Asia and is ancestral to all living bears. Source: Internet
By contrast, the Oligocene–Miocene boundary is not set at an easily identified worldwide event but rather at regional boundaries between the warmer late Oligocene and the relatively cooler Miocene. Source: Internet
As in the Oligocene before it, grasslands continued to expand and forests to dwindle in extent. Source: Internet
Brontotheres died out in the Earliest Oligocene, and creodonts died out outside Africa and the Middle East at the end of the period. Source: Internet
Cooling of the oceans had already commenced by the Eocene/Oligocene boundary, and they continued to cool as the Oligocene progressed. Source: Internet
Extensive research has gone into the fossil floras of the Paleocene to Oligocene of South-Eastern Australia, and has failed to uncover a single Eucalyptus specimen. Source: Internet