Lystrosaurus

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Lystrosaurus
Live reconstruction of Lystrosaurus georgi

Live reconstruction of Lystrosaurus georgi

Temporal occurrence
Changhsingium ( Upper Permian ) to Olenekian ( Lower Triassic )
253.8 to 245.9 million years
Locations
Systematics
Amniotes (Amniota)
Synapsids (Synapsida)
Therapsids (Therapsida)
Anomodontia
Dicynodontia
Lystrosaurus
Scientific name
Lystrosaurus
Cope , 1870

Lystrosaurus is a genus of therapsids ("mammal-like reptiles") from the group of Dicynodontia , which lived during the late Upper Permian ( Zechstein ) and the early Triassic ( red sandstone ) 254 to 246 million years ago. Lystrosaurus fossilshave been found in South Africa , Antarctica , China , India, and European Russia .

The paleobiogeographical distribution areas of Cynognathus , Mesosaurus , Glossopteris and Lystrosaurus shown here in color allow the reconstruction of Gondwana and are therefore evidence of the existence of plate tectonics

Lystrosaurus was one of the few animals that survived the mass extinction at the end of the Permian and was the dominant, herbivorous terrestrial vertebrate in the species-poor period of the Early Triassic that followed .

Its discovery in the Transantarctic Mountains by Edwin H. Colbert and his team in 1969/70 helped to confirm the theory of plate tectonics , because fossils of Lystrosaurus had already been found in deposits of the early Triassic of South Africa, as well as in India and China. Today's continents formed the supercontinent Pangea .

features

Lystrosaurus was a medium-sized, stocky-built animal that was about the size of a pig. It had a short, downward-pointing snout that was toothless with the exception of two enlarged canines in the upper jaw. Originally it was assumed that Lystrosaurus lived amphibiously because of its eyes and nostrils, which were high on the skull, like the hippopotamus . In 1991, two scientists published an alternative view of the way Lystrosaurus lived . Accordingly, the changes in the structure of the skull were an adaptation to very solid, fiber-rich food, typical for plants that grow in arid areas. The wide front feet are also suitable for digging.

Investigations of the growth rings of fossil Lystrosaurus teeth from the Antarctic show that the animals have at least hibernated in the preliminary stages in order to better survive the cold season. In the course of this investigation it was also found that Lystrosaurus was probably warm-blooded .

species

Live reconstruction of Lystrosaurus murrayi
  • Lystrosaurus murrayi ( Huxley , 1859)
  • Lystrosaurus curvatus ( Owen , 1876)
  • Lystrosaurus declivis Owen,
  • Lystrosaurus georgi Kalandadze, 1975
  • Lystrosaurus hedini Young , 1935
  • Lystrosaurus mccaigi Seeley, 1898
  • Lystrosaurus oviceps Haughton, 1915
  • Lystrosaurus platyceps Seeley, 1898
  • Lystrosaurus rajurkari Tripathi & Satsangi, 1963
  • Lystrosaurus robustus Sun, 1973
  • Lystrosaurus shichanggouensis Cheng, 1986
  • Lystrosaurus weidenreichi Young, 1939

gallery

literature

  • Thomas S. Kemp: The Origin & Evolution of Mammals. Oxford University Press, Oxford 2005. ISBN 0-19-850761-5 .
  • Hazel Richardson: Dinosaurs and other prehistoric animals. BLV Verlagsgesellschaft, 2004. ISBN 3-405-16765-5
  • Michael J. Benton : Lystrosaurus geori, a Dicynodont from the lower Triassic of Russia . Journal of Vertebrate Paleontology 25 (2): 402-413, June 2005 ( PDF )

Individual evidence

  1. ^ MR Whitney & CA Sidor. 2020. Evidence of torpor in the tusks of Lystrosaurus from the Early Triassic of Antarctica. Commun Biol 3, 471; doi: 10.1038 / s42003-020-01207-6

Web links

Commons : Lystrosaurus  - collection of images, videos and audio files