- Monolophosaurus
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Monolophosaurus
Temporal range: Middle Jurassic, 165 Ma
Scientific classification Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Dinosauria Order: Saurischia Suborder: Theropoda (unranked): Tetanurae Superfamily: Megalosauroidea[1] Genus: Monolophosaurus
Zhao & Currie 1993Species - M. jiangi Zhao & Currie 1993 (type)
Monolophosaurus (meaning "single-crested lizard", pronounced /ˌmɒnɵˌlɒfəˈsɔrəs/ mon-o-lof-ə-sawr-əs[2]) was a genus of theropod dinosaur from the Middle Jurassic (about 168-161 Ma) of the Shishugou Formation in what is now Xinjiang, China.[3][4] It was named for the single crest on top of its skull. The type and only known individual is estimated at 5 metres (16 ft).[4] The area that Monolophosaurus was found showed signs of water, so it is possible that this dinosaur lived on the shore of lakes or ocean.[citation needed] The Monolophosaurus jiangi IVP 84019 had its 10th and possibly 11th neural spines fractured. The tenth is fused to the eleventh. A series of parallel ridges on one of the specimen's dentaries may represent tooth marks.[5]
Contents
Discovery and classification
Restoration
A nearly complete skeleton was unearthed in 1984. At first, before description in the scientific literature, it was known in the press as "Jiangjunmiaosaurus", a nomen nudum.[3][6]
In 1993 Zhao and Currie named the type species Monolophosaurus jiangi; the species name refers to Jiangjunmiao ("an abandoned desert inn") near which the holotype IVPP 84019 was found.[3][7] Monolophosaurus was originally termed a "megalosaur" and has often since been suggested to be an allosauroid. Carr (2006) even suggested that the "proceratosaurid" "tyrannosauroid" Guanlong was a subadult Monolophosaurus and therefore an "allosauroid",[8] by noting both taxa have a large, thin, and fenestrated midline crest, but this is probably not the case.
Smith et al. (2007) was the first publication to find Monolophosaurus to be a non-neotetanuran tetanuran[9], by noting many characters previously thought to be exclusive of Allosauroidea to have a more wider distribution. Also, Zhao et al. (2009) noted various primitive features of the skeleton suggesting that Monolophosaurus could be one of the most basal tetanuran dinosaurs instead.[10] Benson (2008, 2010) placed Monolophosaurus in a clade with Chuandongocoelurus that is more basal than Megalosauridae and Spinosauridae in the Megalosauroidea.[1][11] Latter, Benson et al. (2010) found the Chuandongocoelurus/Monolophosaurus clade to be outside of Megalosauroidea and Neotetanurae, near the base of Tetanurae.[12]
References
- ^ a b Benson, Roger B. J. (2010). "A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods". Zoological Journal of the Linnean Society 158: 882−935. doi:10.1111/j.1096-3642.2009.00569.x.
- ^ Creisler, Ben (July 7, 2003). "Dinosauria Translation and Pronunciation Guide M". http://www.dinosauria.com/dml/names/dinom.htm. Retrieved August 23, 2010.
- ^ a b c Zhao, Xi-Jin; Currie, Philip J. (1993). "A large crested theropod from the Jurassic of Xinjiang, People's Republic of China". Canadian Journal of Earth Sciences 30: 2027–2036. http://doc.rero.ch/lm.php?url=1000,43,39,20091210005526-ZZ/PAL_E2326.pdf.
- ^ a b Holtz, Thomas R., Jr. (2007). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages. New York: Random House. pp. Genus list "last updated 8/1/2008". ISBN 978-0-375-82419-7.
- ^ Molnar, R. E., 2001, Theropod paleopathology: a literature survey: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 337-363.
- ^ Holley, David (October 23, 1987). "2nd creature was meat-eater: fossil remains of huge dinosaur found in China". Los Angeles Times. http://articles.latimes.com/1987-10-23/news/mn-10753_1_dinosaur-fossil. Retrieved August 23, 2010.
- ^ Brusatte, Stephen L.; Benson, Roger B. J.; Currie, Philip J.; Zhao, Xijin (2010). "The skull of Monolophosaurus jiangi (Dinosauria: Theropoda) and its implications for early theropod phylogeny and evolution". Zoological Journal of the Linnean Society 158: 573–607. doi:10.1111/j.1096-3642.2009.00563.x. http://sites.google.com/site/brusatte/Brusatteetal2010MonolophosaurusSkull.pdf?attredirects=0.
- ^ Carr T. 2006. Is Guanlong a tyrannosauroid or a subadult Monolophosaurus? Journal of Vertebrate Paleontology 26:48A.
- ^ Smith ND, Makovicky PJ, Hammer WR, Currie PJ. 2007. Osteology of Cryolophosaurus ellioti (Dinosauria:Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution. Zoological Journal of the Linnean Society 151: 377–421.
- ^ Zhao, Xijin; Benson, Roger B. J.; Brusatte, Stephen L.; Currie, Philip J. (2010). "The postcranial skeleton of Monolophosaurus jiangi (Dinosauria: Theropoda) from the Middle Jurassic of Xinjiang, China, and a review of Middle Jurassic Chinese theropods". Geological Magazine 147 (1): 13–27. doi:10.1017/S0016756809990240. http://geolmag.geoscienceworld.org/cgi/content/full/147/1/13.
- ^ Benson, 2008. A new theropod phylogeny focussing on basal tetanurans, and its implications for European 'megalosaurs' and Middle Jurassic dinosaur endemism. Journal of Vertebrate Paleontology. 51A.
- ^ Brusatte, Benson, Currie and Zhao, 2010. The skull of Monolophosaurus jiangi (Dinosauria: Theropoda) and its implications for early theropod phylogeny and evolution. Zoological Journal of the Linnean Society. 158(3), 573-607.
Further reading
- Dong Zhiming (1992). Dinosaurian Faunas of China. Beijing: China Ocean Press. ISBN 3-540-52084-8.
External links
- Carr, Thomas (2006). "Is Guanlong a tyrannosauroid or a subadult Monolophosaurus?". Journal of Vertebrate Paleontology 26 (3 Supplement): 48A. http://www.miketaylor.org.uk/tmp/svp-abstracts/SVP%202006%20abstracts.pdf.
- Monolophosaurus in the Dino Directory, The Natural History Museum, London.
Categories:- Dinosaurs of Asia
- Jurassic dinosaurs
- Megalosaurs
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