Agrosaurus: Difference between revisions
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'''''Agrosaurus''''' (Seeley, 1891) (AG-ro-SAW-rus) meaning 'field lizard', referring to the place where it was supposedly discovered, ([[Ancient Greek|Greek]] ''agros'' meaning 'field' and ''sauros'' meaning 'lizard') is the name given to the remains of what is tentatively believed to be a [[Triassic]] [[prosauropod]] from [[Australia]]. This would make it the oldest [[dinosaur]] remains from that country. The [[type species]] is ''Agrosaurus macgillivrayi''. |
'''''Agrosaurus''''' (Seeley, 1891) (AG-ro-SAW-rus) meaning 'field lizard', referring to the place where it was supposedly discovered, ([[Ancient Greek|Greek]] ''agros'' meaning 'field' and ''sauros'' meaning 'lizard') is the name given to the remains of what is tentatively believed to be a [[Triassic]] [[prosauropod]] from [[Australia]]. This would make it the oldest [[dinosaur]] remains from that country. The [[type species]] is ''Agrosaurus macgillivrayi''. |
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The British ship HMS ''Fly'' collected a [[tibia]], a claw and some other fragments in 1844, purportedly from Cape York, Queensland. The original block was purchased by the [[British Museum of Natural History]] in 1879, but the remains were not studied until 1891. |
The British ship HMS ''Fly'' collected a [[tibia]], a claw and some other fragments in 1844, purportedly from Cape York, Queensland. The original block was purchased by the [[British Museum of Natural History]] in 1879, but the remains were not studied until 1891.Harry[[Seeley]] identified it in that year. The block was prepared in the late 1980s. Following the preparation, Ralph [[Molnar]] (1991) noticed similiarities to the prosauropod [[Massospondylus]]. Galton and Cluver (1976) see Agrosaurus as close to [[Anchisaurus]]. Vickers-Rich, Rich, McNamara and Milner (1999) equate Agrosaurus and [[Thecodontosaurus antiquus]], claiming that the British Museum remains were mislabelled. The difficulty in correctly identifying the source of the fossil lies in the fact that the log of the ''Fly'' does not record it. The [[matrix]] in which the prosauropod bones were preserved were tested with rocks of similar age in Cape York and Durdham Downs, the latter being beds where ''Thecodontosaurus'' remains have been found in the Bristol area of England. The English beds compared most favourably. In fact, as early as 1906 [[von Huene]] had described the rock matrix as 'extremely reminiscent of the bone breccia at Durdham Downs near Bristol.' Remains of the jaw of a [[sphenodont]] identical to [[Diphyodontosaurus]] avonis, a lizard-like reptile common to the Bristol Triassic beds has been extracted. |
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If Agrosaurus is not a valid genus, which seems likely, [[Rhoetosaurus]] brownei and [[Ozraptor]] subutaii, both from the [[Bajocian]] (Middle [[Jurassic]]) would be the oldest known Australian dinosaurs. Fortunately they are well documented. |
If Agrosaurus is not a valid genus, which seems likely, [[Rhoetosaurus]] brownei and [[Ozraptor]] subutaii, both from the [[Bajocian]] (Middle [[Jurassic]]) would be the oldest known Australian dinosaurs. Fortunately they are well documented. |
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Revision as of 21:04, 7 December 2006
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| Genus: | Agrosaurus
Seeley, 1891 |
| Species: | Agrosaurus macgilivrayi
Seeeley, 1891 |
Agrosaurus (Seeley, 1891) (AG-ro-SAW-rus) meaning 'field lizard', referring to the place where it was supposedly discovered, (Greek agros meaning 'field' and sauros meaning 'lizard') is the name given to the remains of what is tentatively believed to be a Triassic prosauropod from Australia. This would make it the oldest dinosaur remains from that country. The type species is Agrosaurus macgillivrayi.
The British ship HMS Fly collected a tibia, a claw and some other fragments in 1844, purportedly from Cape York, Queensland. The original block was purchased by the British Museum of Natural History in 1879, but the remains were not studied until 1891.HarrySeeley identified it in that year. The block was prepared in the late 1980s. Following the preparation, Ralph Molnar (1991) noticed similiarities to the prosauropod Massospondylus. Galton and Cluver (1976) see Agrosaurus as close to Anchisaurus. Vickers-Rich, Rich, McNamara and Milner (1999) equate Agrosaurus and Thecodontosaurus antiquus, claiming that the British Museum remains were mislabelled. The difficulty in correctly identifying the source of the fossil lies in the fact that the log of the Fly does not record it. The matrix in which the prosauropod bones were preserved were tested with rocks of similar age in Cape York and Durdham Downs, the latter being beds where Thecodontosaurus remains have been found in the Bristol area of England. The English beds compared most favourably. In fact, as early as 1906 von Huene had described the rock matrix as 'extremely reminiscent of the bone breccia at Durdham Downs near Bristol.' Remains of the jaw of a sphenodont identical to Diphyodontosaurus avonis, a lizard-like reptile common to the Bristol Triassic beds has been extracted.
If Agrosaurus is not a valid genus, which seems likely, Rhoetosaurus brownei and Ozraptor subutaii, both from the Bajocian (Middle Jurassic) would be the oldest known Australian dinosaurs. Fortunately they are well documented.
References
- John A. Long, Dinosaurs of Australia and New Zealand, UNSW Press 1998
- Vickers-Rich, P., T.H.Rich, G.C.McNamara and A.Milner 1999 Agrosaurus: Australia's Oldest Dinosaur? Records of the Western Australian Museum Suppliment No.57: 191-200