Sharovipteryx
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Sharovipteryx , living reconstruction |
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| Middle to Upper Triassic | ||||||||||
| 230 to 225 million years | ||||||||||
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| Sharovipteryx | ||||||||||
| Cowen , 1981 | ||||||||||
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Sharovipteryx is a genus of extinct diapsid reptiles from theCentral Asian Triassic .
Fossil remains of this gliding animal were found in sea sedimentary rocks of the Madygen Formation , a fossil deposit in southwest Kyrgyzstan . The only species Sharovipteryx mirabilis was described as Podopteryx mirabilis by Alexander Grigorjewitsch Scharow (English transcription : Aleksandr Grigorevich Sharov) in 1971 on the basis of a single skeleton find with flying skin impressions (specimen number PIN 2584/8) - but the generic name was already assigned to an insect species, so that by Cowen 1981 the name was changed to Sharovipteryx .
Skeletal features and systematic classification
The skeleton has been preserved from the back and is largely complete, the bones are still in the skeletal structure. Diagnostic features of the genus and species are the clear rearward elongation of the hyoid bone , an extension at the outer end of the thigh bone and an extremely elongated shin , the length of which even exceeds the body of the animal.
A.G. Sharov took 1971, it was stated that sharovipteryx and found also in Madygen Longisquama to thecodonte archosaurs the group Pseudosuchia and justified this with sharovipteryx alone with the clear formation of a forward-facing front of the hip joint pit located extension of the ilium . He was the first to consider a relationship with pterosaurs and the ornithode Scleromochlus .
According to an assignment made by Leonid Tatarinov for the first time in 1989, Sharovipteryx is currently regarded as a representative of the Archosauromorpha group Prolacertiformes . As derived characteristics of this group, which also occur in Sharovipteryx , Unwin and others 2000 list the lengthening of the cervical vertebrae and the low cervical spinous processes . The same authors name other features that the genus shares only with certain members of the Prolacertiformes, including cervical ribs that are long and slender; the presence of seven or fewer cervical vertebrae; a straight thigh that is shorter than the shin; a fourth metatarsal that is less than three times the length of the fifth metatarsal.
Skin preservation and gliding
While the extent of the flight membrane between the arms and the trunk is uncertain due to conservation reasons, the only known fossil shows the impression of a very extensive flight membrane stretched between the hind legs and the tail ( uropatagium ) in a folded state.
Sharovipteryx was one of the first glider pilots to have air skins stretched on the limbs; other gliding reptiles of the Permian and Triassic such as Coelurosauravus , Mecistotrachelos and the Kuehneosauridae had wings that protruded laterally from the body and were stabilized by elongated ribs or a system of additional bone rods .
The position of the limbs and the shape of the wings when unfolded were reconstructed in very different ways by the editors. Based on aerodynamic models, Gary Dyke and others suggested in 2006 that Sharovipteryx be viewed as a delta wing glider with separate triangular flight skins on the arms and legs.
Individual evidence
- ^ Richard Cowen: Homonyms of Podopteryx. In: Journal of Paleontology. Vol. 55, No. 2, ISSN 0022-3360 , p. 483.
- ^ A b Carl Gans, Ilja Darevski, Leonid P. Tatarinov: Sharovipteryx, a reptilian glider? In: Paleobiology. Vol. 13, No. 4, 1987, ISSN 0094-8373 , pp. 415-426, abstract .
- ↑ a b c d David M. Unwin, Vladimir R. Alifanov, Michael J. Benton: Enigmatic small reptiles from the Middle-Late Triassic of Kirgizstan. In: Michael J. Benton, Mikhail A. Shishkin, David M. Unwin, Evgenii N. Kurochkin (Eds.): The age of dinosaurs in Russia and Mongolia. Cambridge University Press, Cambridge et al. 2000, ISBN 0-521-55476-4 , pp. 177-186.
- ↑ Александр Г. Шаров: Новые Летающие Рептилии из Мезозоя Казахстана и Киргизии. In: Академию наук СССР. Труды Палеонтологического Института. Vol. 175, 1980, ISSN 0376-1444 , pp. 7-18, ( New flying reptiles from the Mesozoic of Kazakhstan and Kyrgyzstan. ).
- ↑ Леони́д П. Татаринов: О Систематическом Положении и Образе Жизни Проблематичного Верхнетриасоского ренетриастыкаюого ренетриастыкаювого реемipteryыкаюого реемipteryыкаюого. In: Палеонтологический Журнал. No. 2, 1989, ISSN 0031-031X , pp. 110–112, digitized version (PDF; 453.90 kB) , ( The systematic position and way of life of the problematic Upper Triassic reptile Sharovipteryx mirabilis.).
- ↑ Dietrich Schaller: Wing Evolution. In: Max K. Hecht, John H. Ostrom , Günter Viohl, Peter Wellnhofer (eds.): The Beginnings of Birds. Proceedings of the International Archeopteryx Conference, Eichstätt 1984. Friends of the Jura Museum Eichstätt, Eichstätt 1985, ISBN 3-9801178-0-4 , pp. 333-348.
- ^ A b Gareth J. Dyke, Robert L. Nudds, Jeremy MV Rayner: Flight of Sharovipteryx mirabilis: the world's first delta-winged glider. In: Journal of Evolutionary Biology. Vol. 19, No. 4, 2006 pp. 1040-1043, doi : 10.1111 / j.1420-9101.2006.01105.x .
