Changhsingian

Changhsingian
In the geologic time scale, the Changhsingian or Changxingian is the latest age or uppermost stage of the Permian. It is also the upper or latest of two subdivisions of the Lopingian Epoch or Series. The Changhsingian lasted from to 251.9 Ma ago. It is preceded by the Wuchiapingian age/stage and is followed by the Induan age/stage (Early Triassic epoch).
The greatest mass extinction in the Phanerozoic eon, the Permian–Triassic extinction event, occurred during this age.
Stratigraphic definitions
The Changhsingian is named after Changxing in northern Zhejiang, China. The stage was named for the Changhsing Limestone. The name was first used for a stage in 1970 and was anchored in the international timescale in 1981.
The base of the Changhsingian Stage is at the first appearance of the conodont species Clarkina wangi. The global reference profile is profile D at Meishan, in the type area in Changxing. The top of the Changhsingian (the base of the Induan Stage and the Triassic System is at the first appearance of the conodont species Hindeodus parvus.
The Changhsingian stage contains only one ammonite biozone: that of the genus Iranites.
Changhsingian life
The Changhsingian ended with the Permian–Triassic extinction event, the largest mass extinction event of the Phanerozoic Era, when both global biodiversity and alpha diversity (community-level diversity) were devastated.
Among fishes, the bobasatraniiforms Bobasatrania and Ebenaqua are known from Changhsingian deposits of Greenland and Australia, respectively. Another deep-bodied fish, Sinoplatysomus, is known from Zhejiang province of China, along with the elongate saurichthyiform Eosaurichthys. Several fish genera were described from Changhsingian deposits of Russia and South Africa. The Hambast Formation of Iran yielded chondrichthyan faunas of Wuchiapingian to Changhsingian age.
Changhsingian aged beds of the Tesero Member of the Werfen Formation produced fossils of a crown group echinoid, Eotiaris teseroensis and other taxa.
The Paratirolites Limestone near Julfa (Azerbaijan, Iran) contains a diverse pre-extinction ammonoid fauna, including the genera Neoaganides, Pseudogastrioceras, Dzhulfites, Paratirolites, Julfotirolites, Alibashites, Abichites, Stoyanowites and Arasella
The Bellerophon Formation in northern Italy documents a pre-extinction bivalve community with 26 species adapted to stressful conditions (high temperatures, high salinity, shallow water depths, low oxygen and high terrigenous input).
Notable formations
Ali Bashi Formation (Armenia, Azerbaijan, Iran)
Bellerophon Formation (Italy)
Changxing Formation (Zhejiang, China)
Daptocephalus Assemblage Zone* (South Africa)
Hambast Formation (Iran)
Hopeman Sandstone Formation (Scotland)
Moradi Formation (Niger)
Quartermaster Formation (Texas, USA)
Rangal Coal Measures* (Queensland, Australia)
Schuchert Dal Formation (Greenland)
Tesero Member of the Werfen Formation (Austria, Bosnia and Herzegovina, Italy)
Usili Formation* (Tanzania)
Lower part of Wordie Creek Formation (Greenland)
* Tentatively assigned to the Changhsingian; age estimated primarily via terrestrial tetrapod biostratigraphy
References
External links
GeoWhen Database - Changhsingian
Upper Paleozoic stratigraphic chart at the website of the subcommission for stratigraphic information of the ICS
Permian geochronology
Geological ages