Changhsingian

In the geologic timescale, the Changhsingian or Changxingian (from Chinese: 长兴县, Pinyin: Chángxìng Xiàn, "Changxing County") 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 253.8 ± 0.7 to 251.0 ± 0.7 million years ago (Ma). It was preceded by the Wuchiapingian and followed by the Induan.^[1]

The greatest mass extinction event in the Phanerozoic eon 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 County in China (Wades-Giles transcription: Ch’ang-hsing). The stage was named for the Changhsing Limestone.^[2] The name was first used for a stage in 1970^[3] and was anchored in the international timescale in 1981.^[4]

The base of the Changhsingian stage is at the first appearance of conodont species Clarkina wangi. The global reference profile is profile D at Meishan, in the type area in Changxing.^[4] The top of the Changhsingian (the base of the Induan stage and the Triassic system is at the first appearance of conodont species Hindeodus parvus.

The Changhsingian stage contains only one ammonite biozone: that of the genus Iranites.

Palaeontology

The Changhsingian ended with the Permian-Triassic Extinction Event when both global biodiversity and alpha diversity (community-level diversity) were devastated^[5]. The world after the extinction was almost lifeless, deserted, hot, and dry. Ammonites, fishes, insects, and the tetrapods (cynodonts, amphibians, reptiles, etc.) remained rare and terrestrial ecosystems did not recover for 30M years^[5].

References

Notes

1. ^ See Gradstein et al. (2004) for a detailed geologic timescale
2. ^ The Changhsing Limestone was named by Grabau (1923)
3. ^ By Furnish & Glenister (1970); see also Furnish & Glenister (1973)
4. ^ ^{a b} The Changhsingian stage and its GSSP were described by Jin et al. (1981)
5. ^ ^{a b} Sahney, S. and Benton, M.J. (2008). "Recovery from the most profound mass extinction of all time" (PDF). Proceedings of the Royal Society: Biological 275 (1636): 759–65. doi:10.1098/rspb.2007.1370. PMC 2596898. PMID 18198148. http://journals.royalsociety.org/content/qq5un1810k7605h5/fulltext.pdf. 

Literature

• Furnish, W.M. & Glenister, B.F.; 1970: Permian ammonite Cyclolobus from the Salt Range, West Pakistan, in: Kummel, B. & Teichert, G. (eds.): Stratigraphic boundary problems, Permian and Triassic of west Pakistan, Geological Department of Kansas University, Special Publication 4, pp 158–176.
• Furnish, W.M. & Glenister, B.F.; 1973: Permian stages names, in: Logan, A. & Hills, L.V.: The Permian and Triassic systems and their mutual boundary, Canadian Society of Petroleum Geologists Memoir 2, pp 522–548.
• Grabau, A.W.; 1923: Stratigraphy of China, Part 1: Palaeozoic and lower, Geological Survey of China, 529 pp.
• Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press
• Jin, Y.; Wang, Y.; Henderson, C.; Wardlaw, B.R.; Shen, S. & Cao, C.; 2006: The Global Boundary Stratotype Section and Point (GSSP) for the base of Changhsingian Stage (Upper Permian) Episodes 29(3), p. 175-182, PDF.

External links

• GeoWhen Database - Changhsingian
• Upper Paleozoic stratigraphic chart at the website of the subcommission for stratigraphic information of the ICS