Oplosaurus
From Wikipedia, the free encyclopedia
| Oplosaurus Fossil range: Early Cretaceous |
||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Scientific classification | ||||||||||||||||||||
|
Oplosaurus (meaning "armed or weapon lizard" or "armoured lizard"; see below for discussion) was a genus of sauropod dinosaur from the Barremian-age Lower Cretaceous Wessex Formation of the Isle of Wight, England. It is known from a single tooth usually referred to the contemporaneous "wastebasket taxon" Pelorosaurus, although there is no solid evidence for this.
Contents |
[edit] History and Taxonomy
The usual story about the odd choice of name is that Paul Gervais named this large, well-preserved tooth (BMNH R964) under the mistaken belief that its owner was an armoured dinosaur like Hylaeosaurus (apparently Gideon Mantell suggested this).[1][2] Thus, its name would mean "armoured lizard". However, recent research by Ben Creisler shows that Gervais compared it to Mosasaurus, not Hylaeosaurus, and that the name may have been intended as "armed lizard", with the teeth as the weapons of a carnivore (although this would make the species name redundant, as it too means "armed").[3]
Richard Lydekker (1888) suggested that a maxilla with a tooth (BMNH R751), also from the Isle of Wight, was another example of this animal, but this opinion has not been substantiated.[4]
The tooth is large (85 mm [3.35 in] tall in total, with a spatulate crown 52 mm [2.05 in] tall, comparable to Brachiosaurus; it has a pointed tip, a slightly compressed form "cheek" to tongue, a slight convexity to the base of the tongue-facing side, and wear facets.[3][2] It is vaguely like a Brachiosaurus tooth, which is why the genus is usually referred to Brachiosauridae, and to Pelorosaurus,[5] although Pelorosaurus is based on fragmentary remains that don't include teeth. (See Naish and Martill (2001) for a good review of Oplosaurus and Wealden sauropods in general; here is a more recent informal summation of the state of work.)
Given how poor the Pelorosaurus holotype material is, and that it doesn't include teeth, recent reviews have retained Oplosaurus as a potentially valid but poorly-known genus.[6] Darren Naish, a British palaeontologist familiar with Wealden sauropods, has suggested informally that the genus may be a turiasaur.
[edit] Paleobiology
As Naish and Martill point out, the tooth is comparable in size to that of Brachiosaurus, indicating that the owner was a large sauropod;[2] as a possible turiasaur, the size should not change drastically. It would have been a quadrupedal herbivore, possibly around 25 m (82 ft) long.[2]
[edit] References
- ^ Wright, T. (1852). Contributions to the palaeontology of the Isle of Wight. Annals and Magazine of Natural History 2:87-93.
- ^ a b c d Naish, D., and Martill, D.M. (2001). Saurischian dinosaurs 1: Sauropods. In: Martill, D.M., and Naish, D. (eds.). Dinosaurs of the Isle of Wight. The Palaeontological Association:London 185-241. ISBN 0-901707-72-2
- ^ a b Gervais, P. (1852). Zoologie et paléontologie française (animaux vertébrés) (1st edition). A. Bertrand:Paris, 271 p. [French]
- ^ Lydekker, R. (1888). Note on a new Wealden iguanodont and other dinosaurs. Quarterly Journal of the Geological Society of London 44:46-61.
- ^ McIntosh, J.S. (1990). Sauropoda. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria. University of California Press:Berkeley 345-401. ISBN 0-520-06727-4
- ^ Upchurch, P.M., Barrett, P.M., and Dodson, P. (2004). Sauropoda. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria (2nd edition). University of California Press:Berkeley 259-322. ISBN 0-520-24209-2
