Bumbanian

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The Bumbanian is a regional stage in the terrestrial paleogene of East Asia in the history of the earth . The Bumbanian is the fourth stage in the sequence of the land mammal stages in East Asia and follows the Gashatan , above (or after) the Arshantan . According to the current correlation it corresponds to the lower part of the global ypresian stage of Eozän (Paläogen) (the upper part of the ypresian already correlated with a part of it following Arshantan stage). Geochronologically it is currently dated between 56 and 52 million years. The Bumbanian is characterized by a wave of mammal groups immigrating from North America.

Concept history

The Bumbanian is named after the Bumban member of the Naran Bulak formation in the Nemegt basin (near Tsagan Khushu , southern Gobi , Mongolia ). The term Bumbanian first appeared (?) In 1986 in an article by Philip Gingerich in the science journal Science.

Definition, absolute dating, correlation and subdivision

The beginning of the Bumbanian is characterized by the first appearance of Primates , Perissodactyla , Artiodactyla , Condylarthra and Ctenodactyloidea . This also corresponds to the first appearance of these groups in North America and Europe. In the Bumbanian, the archaic families Micromomyidae , Plesiadapidae , Paramomyidae and Hyopsodontidae appear for the first time in East Asia. In North America they occur as early as the Paleocene; this indicates immigration of these families from North America.

In the Bumbanian, the families Eurymylidae, Mimotonidae , Didymoconidae , Alagomyidae and Prodinoceratidae became extinct . Typical genera are Rhombomylus and Gomphos .

The Gashatan / Bumbanian border is traditionally correlated with the Paleocene / Eocene border. The Bumbanian thus corresponds to the lower part of the global Ypresium level. In absolute terms, the Bumbanian corresponds to the period from 56 to 52 million years.

The Bumbanian stage is divided into three biozones:

supporting documents

Individual evidence

  1. ^ Philip D. Gingerich: Early Eocene Cantius torresi - oldest primate of modern aspect from North America. In: Nature. 319, 1986, pp. 319-321. doi: 10.1038 / 319319a0 (online)
  2. ↑ International Stratigraphic Chart 2012 (PDF)
  3. ↑ The absolute values ​​of the regional levels were determined using the Time Scale Creator 6.0 (October 2012) .
  4. ^ Pieter Missiaen: An updated mammalian biochronology and biogeography for the early Paleocene of Asia. In: Vertebrata Palasiatica. 49, 2011, pp. 29-52. (PDF)

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)
  • Don E. Russell, RJ Zhai: The Paleogene of Asia: mammals and stratigraphy. (= Mémoires du Muséum National d'Histoire Naturelle. Series C, Sciences de la Terre 52). Paris 1987, ISBN 2-85653-140-7 .
  • 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. 2001, ISBN 0-231-08482-X .