Shanghuan

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The Shanghuan is a regional stage in the terrestrial palaeogene of East Asia in the history of the earth . The Shanghuan is the basal stage in the succession of land mammal stages in East Asia and begins in the basal Paleocene (Paleogene). It is followed by the Nongshanian . The Shanghuan is characterized by an endemic fauna of original dormouse relatives (Gliriformes) and Pantodonta . Geochronologically, it is currently dated between 66 and 63.3 million years.

Concept history

The Shanghuan was first proposed by Li & Ting (1983) as a provisional stage of the “Chinese Provincial Age” and correlated with the Puercan and the Torrejonian of the “North American Land Mammal Ages” (NALMA). Ting (1998) suggested it as the basal stage of the Asian Land Mammal Ages (ALMA) . The stage is named after the Shanghu Formation in the Nanxiong Basin in Guangdong Province (southern China).

Definition, absolute dating, correlation and subdivision

The beginning of the Shanghuan was recently defined with the first appearance of the order Pantodonta, which is represented in Asia by the genus Bemalambda , and the first appearance of the order Arctostylopida with the genus Asiostylops . Several mammal orders and families appear for the first time in the fossil record in the Shanghuan, such as the orders Anagalida , Acreodi , Tillodontia and the Condylarthra as well as the families Didymoconidae , Eurymylidae and Mimotonidae . The Shanghuan is characterized by fauna elements that are mostly endemic to Asia.

The Shanghuan is correlated with the Puercan and the Torrejonian of North American Mammalian Stratigraphy (NALMA). The Shanghuan / Nongshanian border is approx. 1 million years before the Torrejonian / Tiffanian border. According to the new correlation of the chronostratigraphic units with the geochronological dating, the Shanghuan lasted from 66–63.3, i.e. around 2.7 million years. According to other authors, the Shanghuan / Nongshanian limit correlates with the Torrejonian / Tiffanian limit. The duration of the stage would be extended by around a million years.

The Shanghuan is divided into two fauna zones:

  • Archaeolambda zone
  • Bemalambda zone

supporting documents

Individual evidence

  1. ↑ International Stratigraphic Chart 2012 (PDF)
  2. ↑ The absolute values ​​of the regional levels were determined using the Time Scale Creator 6.0 (October 2012) .
  3. ^ William C. Clyde, Yongsheng Tong, Kathryn E. Snell, Gabriel J. Bowen, Suyin Ting, Paul L. Koch, Qian Li, Yuanqing Wang, Jin Meng: An integrated stratigraphic record from the Paleocene of the Chijiang Basin, Jiangxi Province (China): Implications for mammalian turnover and Asian block rotations. In: Earth and Planetary Science Letters. 269, 2007, pp. 553-563. (Abstract)

literature

  • C.-K. Li, S.-Y. Ting: The Paleogene mammals of China. In: Bulletin of Carnegie Museum of Natural History. 21, 1983, pp. 1-93.
  • Donald L. Lofgren, Jason A. Lillegraven, William A. Clemens, Philip D. Gingerich, Thomas E. Williamson: Paleocene Biochronology: The Puercan Through Clarkforkian Land Mammal Ages. In: Michael O. Woodburne (Ed.): Late Cretaceous and Cenozoic mammals of North America: biostratigraphy and geochronology. Columbia University Press, New York 2004, ISBN 0-231-13040-6 , pp. 43-105. (online at Google Books)
  • S. Ting: Paleocene and early Eocene land mammal ages of Asia. In: KC Beard, MR Dawson (Eds.): Dawn of the Age of Mammals in Asia. (= Bulletin of Carnegie Museum of Natural History. 34). 1998, pp. 124-147.
  • Wang Yuanqing, Meng Jin, Ni Xijun, Li Chuanku: Major events of Paleogene mammal radiation in China. In: Geological Journal. 42, 2007, pp. 415-430. doi: 10.1002 / gj.1083
  • Spencer G. Lucas: Chinese Fossil Vertebrates. Columbia Univ. Press, New York et al. 2002, ISBN 0-231-08482-X .