The Oligocene Epoch (meaning "slightly recent") extends from 34 million years ago until 23 million years ago, and was a time of great significance in the history of American mammals. Mammals, which blossomed with the disappearance of the dinosaurs at the end of the Cretaceous, expanded both in range and variety during this epoch.
The Oligocene is marked by the start of a generalized cooling, which culminated in the Ice Ages of the Pleistocene, but it still remained relatively warmer than today. The time also saw a reintroduction of vulcanism.
Classic Fossil-Bearing Sites
White River Formation, South Dakota
Dominican Republic amber
Florissant Fossil
Beds, Colorado
A craterform structure 10 km in diameter and 34 million years old is located in the Atlantic Ocean off the shore of New jersey.
Significant Events
First Australian Marsupials
The first evidence for Australian marsupials come from Late Oligocene rocks in Tasmania, although these animals may have already been here for a long time.
Oligocene Graphics
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| Paleosyops |
Oligocene lowland |
Procrax |
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| Merycoidodon |
White River |
Mesohippus |
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