- Marshosaurus
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Marshosaurus
Temporal range: Late Jurassic
Reconstructed skull of Marshosaurus at the Carnegie Museum of Natural History Scientific classification Kingdom: Animalia Phylum: Chordata Class: Sauropsida Superorder: Dinosauria Order: Saurischia Suborder: Theropoda (unranked): Tetanurae Superfamily: Megalosauroidea[1] Genus: Marshosaurus Species: M. bicentesimus Binomial name Marshosaurus bicentesimus
Madsen, 1976Marshosaurus was a genus of medium sized theropod, with a size up to 5 or 6 meters (16 to 20 feet) in length and a skull about 60 cm (2 feet) long. It is known from parts of at least three (possibly four) individuals from the Morrison Formation of Utah and Colorado.
The holotype is a left ilium, or upper pelvis bone found at the Cleveland-Lloyd Quarry in central Utah. It was named by James Madsen (1976) for Othniel Charles Marsh, who described many dinosaur fossils during the Bone Wars. The species name was chosen "in honor of the bicentennial of the United States of America"[2]
Characters on the skeleton show it was an avetheropod, a member of Avetheropoda, a group of more bird-like theropods including Tyrannosaurus, Velociraptor and Allosaurus. Benson (et al., 2009) found it to be a megalosauroid, using a lot of new characters of new Megalosaurus specimens. It lived during the Kimmeridgian (Late Jurassic), approximately 155 - 150 mya.
Paleopathology
One right ilium of a Marshosaurus bicentesimus is deformed by "an undescribed pathology" which probably originated as a consequence of injury. Another specimen has a pathological rib.[3] In a 2001 study conducted by Bruce Rothschild and other paleontologists, 5 foot bones referred to Marshosaurus were examined for signs of stress fracture, but none were found.[4]
References
- ^ Benson, R.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 (4): 882–935. doi:10.1111/j.1096-3642.2009.00569.x.
- ^ Madsen, J. H. 1976. A second new theropod dinosaur from the Late Jurassic of east central Utah. Utah Geology 3(1): 51–60.
- ^ 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.
- ^ Rothschild, B., Tanke, D. H., and Ford, T. L., 2001, Theropod stress fractures and tendon avulsions as a clue to activity: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 331-336.
External links
Categories:- Jurassic dinosaurs
- Megalosaurs
- Dinosaurs of North America
- Morrison fauna
- Theropod stubs
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