In the geologic time scale, the Changhsingian or Changxingian is the latest age or uppermost stage of the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

. It is also the upper or latest of two subdivisions of the

Lopingian The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal terms l ...

Epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided ...

or Series. The Changhsingian lasted from to 251.902 million years ago (Ma). It was preceded by the

Wuchiapingian In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or Series. T ...

and followed by the

Induan The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.902 Ma and Ma (million years ago). The Induan is someti ...

. The greatest mass extinction in the Phanerozoic eon, the

Permian–Triassic extinction event The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, ...

, occurred during this age. The extinction rate peaked about a million years before the end of this stage.

Stratigraphic definitions

The Changhsingian is named after Changxing () in northern

Zhejiang Zhejiang ( or , ; , also romanized as Chekiang) is an eastern, coastal province of the People's Republic of China. Its capital and largest city is Hangzhou, and other notable cities include Ningbo and Wenzhou. Zhejiang is bordered by Ji ...

, China. The stage was named for the Changhsing Limestone. The name was first used for a stage in 1970; 1973: ''Permian stages names'', in: : ''The Permian and Triassic systems and their mutual boundary'',

Canadian Society of Petroleum Geologists The Canadian Society of Petroleum Geologists (CSPG) is a professional geological society in Canada. The CSPG works to advance the science of geology, foster professional development of members and promote community awareness of the profession. T ...

Memoir 2, pp 522–548. and was anchored in the international timescale in 1981.; 2006: ''The Global Boundary Stratotype Section and Point (GSSP) for the base of Changhsingian Stage (Upper Permian)'' Episodes 29(3), p. 175-182
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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 A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and express ...

is at the first appearance of the conodont species '' Hindeodus parvus''. The Changhsingian stage contains only one ammonite biozone: that of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Iranites''.

Palaeontology

The Changhsingian ended with the

when both global biodiversity and

alpha diversity In ecology, alpha diversity (α-diversity) is the mean species diversity in a site at a local scale. The term was introduced by R. H. WhittakerWhittaker, R. H. (1960) Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monograp ...

(community-level diversity) were devastated. The world after the extinction was almost lifeless, deserted, hot, and dry. Ammonoids, fishes, insects, and the tetrapods ( cynodonts, amphibians, reptiles, therapsids, etc.) remained rare and terrestrial ecosystems did not recover for 30 million years.

References

External links

GeoWhen Database - ChanghsingianUpper Paleozoic stratigraphic chart
at the website of the subcommission for stratigraphic information of the ICS {{Geological history, p, p Permian geochronology Geological ages