Thecodontosaurus
Thecodontosaurus | |
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Skeletal restoration | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | †Sauropodomorpha |
Family: | †Thecodontosauridae |
Genus: | †Thecodontosaurus Riley & Stutchbury , 1836
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Type species | |
†Thecodontosaurus antiquus Morris, 1843
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Synonyms[1] | |
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Thecodontosaurus ("socket-tooth lizard") is a
age).Its remains are known mostly from Triassic "fissure fillings" in
Discovery and naming
Thecodontosaurus antiquus
In the autumn of 1834,
The original
Other species
Apart from the original
On one occasion, material of Thecodontosaurus was, by mistake, described as a separate genus. In 1891,
Presently, the only valid species is thus T. antiquus.
Misassigned species
- Thecodontosaurus latespinatus von Huene, 1907-08 = Tanystropheus
- Thecodontosaurus primus von Huene, 1907-1908 = indeterminate archosauromorph, previously and questionably referred to Protanystropheus[10]
- Thecodontosaurus elizae Sauvage, 1907
- Thecodontosaurus gibbidens Cope, 1878 = Galtonia
- Thecodontosaurus skirtopodus (Seeley, 1894) = Hortalotarsus
- Thecodontosaurus polyzelus (Hitchcock, 1865) von Huene, 1906
- Thecodontosaurus hermannianus von Huene, 1908
- Thecodontosaurus diagnosticus Fraas, 1912 = Efraasia
- Thecodontosaurus minor Haughton, 1918
- Thecodontosaurus dubius Haughton, 1924[11]
- Thecodontosaurus browni (Seeley, 1895) von Huene, 1932
- Thecodontosaurus alophos Haughton, 1932 = Nyasasaurus[12][13]
Thecodontosaurus caducus was named by Adam Yates in 2003 for a juvenile specimen found in Wales;[14] in 2007 this was made the separate genus Pantydraco.[15] However, Ballell, Rayfield & Benton (2020) considered Pantydraco caducus to be a taxon of uncertain validity, and considered it possible that it might represent a juvenile of Thecodontosaurus antiquus.[16]
Description
From the fragmentary remains of Thecodontosaurus, most of the skeleton can be reconstructed, except for the front of the skull. Thecodontosaurus had a rather short neck supporting a fairly large skull with large eyes. Its jaws contained many small- to medium-sized, serrated, leaf-shaped teeth. This dinosaur's hands and feet each had five digits, and the hands were long and rather narrow, with an extended claw on each. This dinosaur's front limbs were much shorter than the legs, and its tail was much longer than the head, neck and body put together. On average, it was 1.2 metres (3.9 ft) long, 30 centimetres (12 in) or 1 ft. tall, and weighed 11 kilograms (24 lb). The largest individuals had an estimated length of 2.5 metres (8.2 ft).
In 2000,
The small size has been explained as an instance of insular dwarfism.[17]
Classification
Riley and Stutchbury originally saw Thecodontosaurus as a member of the
Modern exact
Paleobiology
Examination of Thecodontosaurus revealed it was exclusively bipedal. Studies of the muscle attachments in its fore and hindlimbs suggest that it was an extremely fast bipedal runner that relied on its weaker front limbs for grasping vegetation, cutting it up and feeding it into its mouth. Its advanced running capabilities suggest it was well adapted for high-speed sprinting, probably as a means of escaping predators.[21]
References
- ^ a b M.J. Benton, L. Juul, G.W. Storrs and P.M. Galton, 2000, "Anatomy and systematics of the prosauropod dinosaur Thecodontosaurus antiquus from the upper Triassic of southwest England", Journal of Vertebrate Paleontology 20(1): 77-108
- ISBN 978-0-226-14374-3.
- ^ Williams, (1835), "Discovery of Saurian Bones in the Magnesian Conglomerate near Bristol", American Journal of Science and Arts 28: 389
- ^ Riley, H., and Stutchbury, S., (1836), "A description of various fossil remains of three distinct saurian animals discovered in the autumn of 1834, in the Magnesian Conglomerate on Durdham Down, near Bristol", Proceedings of the Geological Society of London 2:397–399
- ^ Morris, J., 1843, A Catalogue of British Fossils. British Museum, London, 222 pp
- ^ A.S. Woodward and C.D. Sherborn, 1890, A Catalogue of British Fossil Vertebrat Dulao & Company, London pp. 396
- ^ F. v. Huene, 1908, "On phytosaurian remains from the Magnesian Conglomerate of Bristol (Rileya platyodon)", Annals and Magazine of Natural History, series 8 1: 228-230
- ^ Seeley, H.G., 1891, "On Agrosaurus macgillivrayi, a saurischian reptile from the northeast coast of Australia", Quarterly Journal of the Geological Society of London 47: 164–165
- ^ Vickers-Rich, P., Rich, T.H., McNamara, G.C. & Milner, A. (1999). "Agrosaurus: Australia's oldest dinosaur?". Records of the Western Australian Museum Supplement 57: 191-200
- S2CID 133166493.
- ^ Haughton, S.H., 1924, "The fauna and stratigraphy of the Stormberg Series", Annals of the South African Museum 12: 323–497
- ^ S.H. Haughton, 1932, "On a collection of Karroo vertebrates from Tanganyika Territory", Quarterly Journal of the Geological Society of London 88(4): 634-671
- ^ Nesbitt, S. J.; Barrett, P. M.; Werning, S.; Sidor, C. A.; Charig, A. J. (2013). "The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania". Biol. Lett. doi:10.1098/rsbl.2012.0949.
- ^ Yates, A. M. (2003). "A new species of the primitive dinosaur Thecodontosaurus (Saurischia: Sauropodomorpha) and its implications for the systematics of early dinosaurs". Journal of Systematic Palaeontology 1(1): 1-42
- ^ Galton, P.M., Yates, A.M., & Kermack, D. (2007). "Pantydraco n. gen. for Thecodontosaurus caducus Yates, 2003, a basal sauropodomorph dinosaur from the Upper Triassic or Lower Jurassic of South Wales, UK". Neues Jahrbuch für Geologie und Paläontologie, Abh., 243: 119-125
- .
- ^ Whiteside, D.I. and Marshall, J.E.A. (2008) "The age, fauna and palaeoenvironment of the Late Triassic fissure deposits of Tytherington, South Gloucestershire, UK". Geological Magazine, 14(1): 105-147
- doi:10.1144/gsl.jgs.1870.026.01-02.09 – via Wikisource.
- ^ Upchurch, P. (1998). "The phylogenetic relationships of sauropod dinosaurs". Zool. J. Linnean Soc. 124: 43–103
- Proc. R. Soc. Lond.: B Biol Sci. 2003 Aug 22; 270(1525): 1753–8
- PMID 35116154.
Further reading
- Moody, Richard. Dinofile. Pg. 23. Octopus Publishing Group Ltd., 2006
Data related to Thecodontosaurus at Wikispecies