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Magnosaurus
''Magnosaurus'' (meaning 'large lizard') was a genus of basal tetanuran theropod dinosaur from the Middle Jurassic of England. It is based on fragmentary remains and has often been confused with or included in ''Megalosaurus''.
==History and taxonomy==
In 1923, Friedrich von Huene named ''Megalosaurus nethercombensis'' from a partial skeleton (OUM J12143) from the Aalenian-Bajocian-age Middle Jurassic Inferior Oolite, found in the nineteenth century by W. Parker near Nethercomb, north of Sherborne, in Dorset, England. The material included partial dentaries, dorsal and caudal vertebrae, a partial ilium, a partial right pubis, internal casts of the femora, and tibiae, from a possibly juvenile individual. Huene interpreted it as a more primitive species of ''Megalosaurus''.〔von Huene, F. (1923). Carnivorous Saurischia in Europe since the Triassic. ''Bulletin of the Geological Society of America'' 34:449-458.〕
In 1926, he named the tooth species ''Megalosaurus lydekkeri'' for a specimen, BMNH 41352, from the Lower Lias (Lower Jurassic) of England that Richard Lydekker had first described in 1888.〔von Huene, F. (1926). The carnivorous Saurischia in the Jura and Cretaceous formations, principally in Europe. ''Revista del Museo de La Plata'' 29:35-167.〕〔Lydekker, R. (1888). ''Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria''. British Museum (Natural History):London, 309 p.〕 Finally, in 1932, he created the genus ''Magnosaurus'' for ''M. nethercombensis'', referred ''M. lydekkeri'' to it, and created a third species, ''M. woodwardi'', for the genus. ''M. woodwardi'' was based on a tibia (BMNH R.3542) from the Lower Lias, which he simultaneously and accidentally also named ''Sarcosaurus andrewsi'';〔von Huene, F. (1932). ''Die fossile Reptil-Ordnung Saurischia, ihre Entwicklung und Geschichte''. Monographien zur Geologie und Palaeontologie 1(4) ()〕 in 1956 the latter name was given priority by von Huene. Even more confusing, in the same 1932 publication von Huene renamed ''Sarcosaurus woodi'' into ''Magnosaurus woodi''.
Until the 1990s, the genus had been ignored as a species of ''Megalosaurus''.〔Waldman, M. (1974). "Megalosaurids from the Bajocian (Middle Jurassic) of Dorset". ''Palaeontology'' 17(2):325-339.〕 However, with growing concern over what exactly is constituted by ''Megalosaurus'', ''Magnosaurus'' has been generally separated as its own genus.〔Molnar, R.E., Kurzanov, S.M., and Dong, Z. (1990). "Carnosauria". In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.), ''The Dinosauria''. University of California Press:Berkeley and Los Angeles, p. 169-209. ISBN 0-520-06727-4〕〔Rauhut, O.W.M. (2003). "The Interrelationships and Evolution of Basal Theropod Dinosaurs." ''Special Papers in Palaeontology'' 69. The Palaeontological Association:London, 213 p.〕〔Holtz Jr., T.R., Molnar, R.E., and Currie, P.J. (2004). "Basal Tetanurae". In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.), ''The Dinosauria'' (second edition). Berkeley: University of California Press:Berkeley, p. 71-110. ISBN 0-520-24209-2〕 Also, there are morphological differences: for example, possible ''Megalosaurus'' tibiae are compressed at the far end, unlike those of ''Magnosaurus''.〔 Rauhut (2003) considered it and ''Eustreptospondylus'' to be the same genus, because the two share a similarly expanded front tip of the dentary and enlarged third dentary tooth. He therefore renamed ''Eustreptospondylus oxoniensis'' a ''Magnosaurus oxoniensis'' but this has not been generally followed.〔 Reviews have found it to most likely be a basal tetanuran, probably a megalosaurid.〔〔Paul, G.S. (1988). ''Predatory Dinosaurs of the World.'' Simon & Schuster:New York, 464 p. ISBN 0-671-61946-2〕 A detailed redescription by Roger Benson in 2010 concluded ''Magnosaurus'' was valid taxon, a megalosaurid megalosauroid, and at about 175 million years old the oldest certain known member of the Tetanurae.〔Benson, Roger B. J., 2010, "The osteology of ''Magnosaurus nethercombensis'' (Dinosauria, Theropoda) from the Bajocian (Middle Jurassic) of the United Kingdom and a re-examination of the oldest records of tetanurans", ''Journal of Systematic Palaeontology'', 8(1): 131-146〕
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