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Triassic–Jurassic extinction event
The Triassic–Jurassic extinction event marks the boundary between the Triassic and Jurassic periods, ,〔
Some sources (Whiteside et al 2010) give a date 201.4 Ma.〕 and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas, a whole class (conodonts)〔(The extinction of conodonts —in terms of discrete elements— at the Triassic-Jurassic boundary )〕 and 34% of marine genera disappeared. On land, all pseudosuchians (non-dinosaurian archosaurs) other than crocodylomorphs (Sphenosuchia and Crocodyliformes), some remaining therapsids, and many of the large amphibians became extinct.
== Impact ==
At least half of the species now known to have been living on Earth at that time went extinct. This event vacated terrestrial ecological niches, allowing the dinosaurs to assume the dominant roles in the Jurassic period. This event happened in less than 10,000 years and occurred just before Pangaea started to break apart. In the area of Tübingen (Germany), a Triassic-Jurassic bonebed can be found, which is characteristic for this boundary.〔Johannes Baier: (''Der Geologische Lehrpfad am Kirnberg (Keuper; SW-Deutschland)'' ). - Jber. Mitt. oberrhein. geol. Ver, N. F. 93, 9-26, 2011.〕
Statistical analysis of marine losses at this time suggests that the decrease in diversity was caused more by a decrease in speciation than by an increase in extinctions.
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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