Information AboutMiocene Epoch |
| CATEGORIES ABOUT MIOCENE | |
| miocenemiocene | |
| neogene | |
| SHOPPER'S DELIGHT | |
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The Miocene boundaries are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Oligocene and the cooler Pliocene . MIOCENE SUBDIVISIONS The Miocene Faunal Stage s from youngest to oldest are: The subdivisions within the Miocene are defined by the relative abundance of different species of calcareous nanofossils ( Calcite platelets shed by brown single-celled algae) and Foraminifera (single-celled protists with diagnostic shells). MIOCENE CLIMATE Climates remained moderately warm although the slow global cooling that eventually led to the Pleistocene Glaciation s continued. Although a long-term cooling trend was well underway, there is evidence for a warm period during the Miocene when the global climate rivalled that of the Oligocene . The Miocene warming began 21 million years ago and continued until 14 million years ago, when global temperatures took a sharp drop. By 8 million years ago, temperatures dropped sharply once again, and the Antarctic ice sheet was already approaching its present-day size and thickness. Greenland may have begun to have large glaciers as early as 7 to 8 million years ago, although the climate for the most part remained warm enough to support forests there well into the Pliocene . MIOCENE PALEOGEOGRAPHY Continents continued to Drift toward their present positions. Of the modern geologic features, only the land bridge between South America and North America was absent. Mountain building took place in Western North America and Europe . Both continental and marine Miocene deposits are common worldwide with marine outcrops common near modern shorelines. Well studied continental exposures occur in the American Great Plains and in Argentina . MIOCENE FLORA Grasslands underwent a major expansion as forests fell victim to a generally cooler and drier climate overall. Grasses also diversified greatly into a number of species and also caused a major increase in the biodiversity of large herbivores, including ruminants (of which modern cattle and deer belong to). MIOCENE FAUNA Both marine and continental Fauna were fairly modern. Only in isolated South America and Australia did widely divergent fauna exist. Mammals Recognizable Wolves , Horse s, Beaver , Deer , Camel s, Whale s, etc. existed in the Miocene. Birds Recognizable Crow s, Duck s, Auk s, and Owl s appear in the Miocene. MIOCENE OCEANS The oceans continue cooling, and Brown Alga e plants, called Kelp , proliferate, supporting new species of sea life, including Otter s, Fish and various Invertebrate s. SEE ALSO REFERENCES
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