Arizonasaurus
| Arizonasaurus | ||||||||||||
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Arizonasaurus babbitti , life reconstruction |
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| Temporal occurrence | ||||||||||||
| Middle Triassic | ||||||||||||
| approx. 240 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Arizonasaurus | ||||||||||||
| Welles , 1947 | ||||||||||||
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Arizonasaurus ("Lizard from Arizona") is a genus of theextinct Rauisuchia from the Central Triassic of North America,which belongs to the basal archosaurs .
In 1947, Samuel Paul Welles published the first scientific description of the genus and its type A. babbitti on the basis of a single upper jawbone from the Moenkopi Formation near Holbrook in the US state of Arizona . Another find of a half complete skeleton in 2002 clarified the description of the animal and the systematic assignment.
Fossil description
The holotype of A. babbitti consists of a single bone of the left upper jaw , which differs from other known species by a typically shaped triangular appendage. In 2002, a number of isolated archosaur bones , including parts of the spine , skull and pelvis , were found in the formation by Dylan Rust . The parts were described in 2003 by Sterling J. Nesbitt as a roughly 50 percent preserved skeleton of a sub- adult individual of A. babbitti , whereby he pointed out the almost identical maxillary bones.
Find location
All of the A. babbitti fossil finds come from the upper Moenkopi Formation in Arizona, USA. This is due to the presence of the temnospondyli counting Eocyclotosaurus and Magnetostratigraphy to the Middle Triassic, more to the Anisian , dated before about 240 million years ago.
Systematics
A. babbitti could be classified into the probably not monophyletic ' Rauisuchia ' and here in the Poposauridae or the Ctenosauriscidae , a very closely related group , based on the finds from 2002 . In earlier attempts to systematically classify Arizonasaurus , it was assigned to groups as diverse as the dinosaurs , the Trilophosauridae , the Stagonolepididae , the Proterosuchia and also the Erythrosuchidae .
literature
- Samuel P. Welles: Vertebrates from the Upper Moenkopi Formation of the Northern Arizona. In: University of California. Bulletin of the Department of Geological Sciences. Vol. 27, No. 7, 1947, ZDB -ID 590824-3 , pp. 241-294.
- Sterling J. Nesbitt: Arizonasaurus and its implications for archosaur divergence. In: Proceedings of the Royal Society. Series B: Biological Sciences. Vol. 270, Supplement 2, 2003, ISSN 0080-4649 , pp. S234-S237, ( doi : 10.1098 / rsbl.2003.0066 ).
- Sterling J. Nesbitt: Osteology of the Middle Triassic pseudosuchian archosaur Arizonasaurus babbitti. In: Historical Biology. Vol. 17, No. 1/4, 2005, ISSN 0891-2963 , pp. 19-47, doi : 10.1080 / 08912960500476499 .
- David J. Gower, Sterling J. Nesbitt: The Braincase of Arizonasaurus babbitti - Further evidence for the Non-Monophyly of 'Rauisuchian' Archosaurs. In: Journal of Vertebrate Paleontology. Vol. 26, No. 1, 2006, ISSN 0272-4634 , pp. 79-87, doi : 10.1671 / 0272-4634 (2006) 26 [79: TBOABE] 2.0.CO; 2 .
