Biology:Steneosaurus megarhinus
| "Steneosaurus" megarhinus | |
|---|---|
Scientific classification 
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| Missing taxonomy template (fix): | Archosauria/Reptilia |
| Clade: | Pseudosuchia |
| Clade: | Crocodylomorpha |
| Clade: | Crocodyliformes |
| Suborder: | †Thalattosuchia |
| Genus: | †Steneosaurus |
| Species: | †S. megarhinus
|
| Binomial name | |
| †Steneosaurus megarhinus (Hulke, 1871)
| |
"Steneosaurus" megarhinus is an extinct species of teleosaurid thalattosuchian from Late Jurassic (Kimmeridgian) marine deposits in England and France .
Description
"Steneosaurus" megarhinus can be distinguished from other derived teleosaurids in the following characteristics: strongly ventrally deflected anterior margin of the premaxilla; five premaxillary alveoli, the caudal-most being considerably reduced in size; anterodorsally oriented external nares; conical teeth bearing carinae which are only visible on the apical third of the crown. Other salient diagnostic characters can be found in the tooth count, shape of external nares and strong premaxillary deflection. The longirostrine condition of the rostrum mirrors all other species traditionally assigned to Steneosaurus except S. brevior and S. edwardsi.[1]
Taxonomy
"Steneosaurus" megarhinus was originally described as a new species of Teleosaurus, T. megarhinus, by John Whitaker Hulke in 1871 on the basis of NHMUK PV OR 43086, an incomplete snout from the Kimmeridge Clay Formation of Kimmeridge Bay in Dorset, England.[2] In his 1888 catalog of extinct reptiles and amphibians preserved in the Natural History Museum, Richard Lydekker referred it to Steneosaurus, as S. megarhinus.[3] Delair (1958) did not accept the attribution of T. megarhinus to Steneosaurus,[4] and a 2005 cladistic recovered the species as closer to Teleosaurus than to other species traditionally assigned to Steneosaurus.[5] A preliminary report indicates that "Steneosaurus" megarhinus is distinct from all other Middle-Late Jurassic teleosaurids and deserves its own genus.[1]
Distribution
Three specimens are known for "Steneosaurus" megarhinus: the holotype NHMUK PV OR43086, DORCM G..5067i-v, (both of them incomplete snouts from Kimmeridge Bay, Dorset), and a complete skull from the slightly older Aulacostephanus eudoxus Sub-Boreal ammonite Zone of “La Crouzette”, Francoulès, in Quercy, France.[1]
References
- ↑ 1.0 1.1 1.2 Foffa D, Young MT, Brusatte SL, Steel L. (2015) New specimen and revision of the late Jurassic teleosaurid 'Steneosaurus’ megarhinus. PeerJ PrePrints 3:e1351v1 https://doi.org/10.7287/peerj.preprints.1351v1
- ↑ Hulke, J. W., 1871, Note on a Fragment of a Teleosaurian snout from Kimmeridige Bay, Dorset: Quarterly Journal of the Geological Society of London, v. 17, p. 442-443.
- ↑ 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, 1-309.
- ↑ J. B. Delair. 1958. The Mesozoic reptiles of Dorset. Part one. Proceedings of the Dorset Natural History and Archaeological Society 79:47-72.
- ↑ Mueller-Töwe, I. J. 2005. Phylogenetic relationships of the Thalattosuchia. Zitteliana A45: 211-213.
Wikidata ☰ Q41168134 entry
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