19 Facts About Oligocene


Oligocene is a geologic epoch of the Paleogene Period and extends from about 33.

FactSnippet No. 1,623,850

The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany.

FactSnippet No. 1,623,851

The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch.

FactSnippet No. 1,623,852

The Oligocene is the third and final epoch of the Paleogene Period.

FactSnippet No. 1,623,853

Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene.

FactSnippet No. 1,623,854

Major changes during the Oligocene included a global expansion of grasslands, and a regression of tropical broad leaf forests to the equatorial belt.

FactSnippet No. 1,623,855

Lower boundary of the Oligocene is placed at the last appearance of the foraminiferan genus Hantkenina in a quarry at Massignano, Italy.

FactSnippet No. 1,623,856

Upper boundary of the Oligocene is defined by its GSSP at Carrosio, Italy, which coincides with the first appearance of the foraminiferan Paragloborotalia kugleri and with the base of magnetic polarity chronozone C6Cn.

FactSnippet No. 1,623,857

The Obik Sea, which had separated Europe from Asia, retreated early in the Oligocene, creating a persistent land connection between the continents.

FactSnippet No. 1,623,858

However, towards the end of the Oligocene, there was a brief marine incursion in Europe.

FactSnippet No. 1,623,859

Climate during the Oligocene reflected a general cooling trend following the Early Eocene Climatic Optimum.

FactSnippet No. 1,623,860

Evidence of a relatively warm Oligocene suggests an enigmatic climate state, neither hothouse nor icehouse.

FactSnippet No. 1,623,861

The late Oligocene warming is discernible in pollen counts from the Tibetan Plateau, which show that the south Asian monsoon had already developed by the late Oligocene.

FactSnippet No. 1,623,862

The cooling trend that began in the middle Eocene continued into the Oligocene, bringing the poles well below freezing for the first time in the Phanerozoic.

FactSnippet No. 1,623,863

Oi1 event of the Eocene-Oligocene transition covered the continent of Antarctica with ice sheets, leaving Nothofagus and mosses and ferns clinging to life around the periphery of Antarctica in tundra conditions.

FactSnippet No. 1,623,864

The cooling of central North America at the Eocene-Oligocene transition resulted in a large turnover of gastropods, amphibians, and reptiles.

FactSnippet No. 1,623,865

Egypt in the Oligocene was an environment of lush forested deltas.

FactSnippet No. 1,623,866

The marine animals of Oligocene oceans resembled today's fauna, such as the bivalves.

FactSnippet No. 1,623,867

Oligocene sees the beginnings of modern ocean circulation, with tectonic shifts causing the opening and closing of ocean gateways.

FactSnippet No. 1,623,868