The Permian is a geologic period and system which extends from to million years ago.〔(【引用サイトリンク】ICS">International Chronostratigraphic Chart )〕 It is the last period of the Paleozoic, following the Carboniferous and preceding the Triassic of the Mesozoic. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the ancient kingdom of Permia.
The Permian witnessed the diversification of the early amniotes into the ancestral groups of the mammals, turtles, lepidosaurs and archosaurs. The world at the time was dominated by a single supercontinent known as Pangaea, surrounded by a global ocean called Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, who could better cope with these drier conditions, rose to dominance in place of their amphibian ancestors.
The Permian (along with the Paleozoic) ended with the largest mass extinction in Earth's history, in which nearly 90% of marine species and 70% of terrestrial species died out.〔http://www.sciencedaily.com/articles/p/permian-triassic_extinction_event.htm〕 It would take well into the Triassic for life to recover from this catastrophe.〔(【引用サイトリンク】title=GeoKansas--Geotopics--Mass Extinctions )〕 Recovery from the Permian-Triassic extinction event was protracted; on land, ecosystems took 30 million years to recover.
== Discovery ==
The term "Permian" was introduced into geology in 1841 by Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil.〔Benton, M.J. et al., (Murchison’s first sighting of the Permian, at Vyazniki in 1841 ), Proceedings of the Geologists' Association, accessed 2012-02-21〕〔Murchison, Roderick Impey (1841) ("First sketch of some of the principal results of a second geological survey of Russia," ) ''Philosophical Magazine and Journal of Science'', series 3, 19 : 417-422. From p. 419: "The carboniferous system is surmounted, to the east of the Volga, by a vast series of marls, schists, limestones, sandstones and conglomerates, to which I propose to give the name of "Permian System," … ."〕 The region now lies in the Perm Krai of Russia.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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