Cryolophosaurus

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Cryolophosaurus
Reconstructed skull of Cryolophosaurus ellioti

Reconstructed skull of Cryolophosaurus ellioti

Temporal occurrence
Lower Jurassic ( Sinemurian to Pliensbachian )
199.3 to 182.7 million years
Locations
Systematics
Dinosaur (dinosauria)
Lizard dinosaur (Saurischia)
Theropoda
Neotheropoda
Cryolophosaurus
Scientific name
Cryolophosaurus
Hammer & Hickerson , 1994
Art
  • Cryolophosaurus ellioti

Cryolophosaurus ("frozen crested lizard") is a genus of theropod dinosaur from the Lower Jurassic , whose fossil remains were discovered on the slope of Mount Kirkpatricks on the Antarctic mainland.

Description and system

Head study of Cryolophosaurus ellioti

Like all theropods , the six to eight meter long Cryolophosaurus moved on two legs ( biped ) and ate meat. There were three claws on its claws. The skull had a peculiarity with a forward-facing bone crest on the nasal bone . The dinosaur also had small ridges over its eyes. It is speculated that this comb was used to attract potential mates during the mating season.

Cryolophosaurus lived during the Lower Jurassic ( Sinemurian to Pliensbachian ) when today's Antarctic continent was still part of the southern supercontinent of Gondwana . Its systematic position is controversial as it had both primitive and modern features. Smith and colleagues (2007) classified it together with Dilophosaurus wetherilli , Dracovenator regenti and "Dilophosaurus" sinensis (or Sinosaurus ) in the now controversial Dilophosauridae family . Carrano et al. (2012) see differences between Cryolophosaurus , "Dilophosaurus" sinensis and the other Dilophosaurids and describe the two as primitive Tetanurae . In more recent works he sometimes appears again as a relative of Dilophosaurus .

It is the first dinosaur found and scientifically described in Antarctica. The name "Cryolophosaurus" refers to both the unusual find situation and the unusual anatomy of the skull.

Find history

Size comparison of C. ellioti with a human.

William R. Hammer and William J. Hickerson published the scientific description of Cryolophosaurus ellioti in 1994 . His fossils were found in 1991 by a research group led by the US American Professor Hammer at an altitude of about 4,100 meters on the slope of Mount Kirkpatrick in the volcanic siltstone of the Hanson Formation. Further remains were discovered in 2003, and the expedition members recovered around half of the skeleton.

The discovery of Cryolophosaurus confirmed that the dinosaurs also spread to Antarctica. The earth's climate was milder then than it is today, but there were also months in the Jura when the temperature could drop below zero degrees Celsius. It can therefore be assumed that Cryolophosaurus was a warm-blooded animal .

literature

  • Darren Naish: The Fascinating Discovery of the Dinosaurs. Konrad Theiss Verlag GmbH, Stuttgart 2010, ISBN 978-3-8062-2325-5 .

Individual evidence

  1. ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 76, online .
  2. ^ Nathan D. Smith, Peter J. Makovicky , William R. Hammer, Philip J. Currie : Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution. In: Zoological Journal of the Linnean Society. Vol. 151, No. 2, 2007, pp. 377-421, doi: 10.1111 / j.1096-3642.2007.00325.x .
  3. ^ Matthew T. Carrano, Roger BJ Benson, Scott D. Sampson: The phylogeny of Tetanurae (Dinosauria: Theropoda). In: Journal of Systematic Palaeontology. Vol. 10, No. 2, 2012, ISSN  1477-2019 , pp. 211-300, doi: 10.1080 / 14772019.2011.630927 .
  4. ^ Zahner, M., & Brinkmann, W. (2019). A Triassic averostran-line theropod from Switzerland and the early evolution of dinosaurs. Nature ecology & evolution, 3 (8), 1146-1152. doi: 10.1038 / s41559-019-0941-z
  5. Dal Sasso, C., Maganuco, S., & Cau, A. (2018). The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds. PeerJ, 6, e5976. doi: 10.7717 / peerj.5976
  6. Nathan D. Smith, Peter J. Makovicky, Diego Pol, William R. Hammer, Philip J. Currie: The dinosaurs of the Early Jurassic Hanson Formation of the Central Transantarctic Mountains: Phylogenetic review and synthesis. In: Alan Cooper, Carol Raymond, and the 10th ISAES Editorial Team (Eds.): Antarctica. A Keystone in a Changing World (= USGS Open-File Report 2007-1047 = Short Research Paper 003). Proceedings of the 10th International Symposium on Antarctic Earth Sciences, Santa Barbara, California, USA - August 26 to September 1, 2007. National Academies Press, Washington DC 2008, ISBN 978-0-309-11854-5 , doi: 10.3133 / of2007 -1047.srp003 , digital version (PDF; 3.01 MB) .

Web links

Commons : Cryolophosaurus  - Collection of images, videos and audio files