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Coniasaurus is an extinct genus of Late Cretaceous marine squamates that range in age from Cenomanian to Santonian.[1] It was first described by Richard Owen in 1850 from lower Cenomanian chalk deposits in South East England (Sussex).[2][3] Two species have been described from this genus: C. crassidens (Owen, 1850), known from Cenomanian to Santonian deposits from South East England, Germany and North America, and C. gracilodens (Caldwell, 1999) from the Cenomanian of southeast England.[1]

Coniasaurus
Temporal range: Late Cretaceous, 100–84 Ma
C. crassidens holotype, drawn by James Erxleben in 1850
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Dolichosauridae
Genus: Coniasaurus
Owen, 1850
Species
  • C. crassidens Owen, 1850 (type)
  • C. gracilodens Caldwell, 1999

Coniasaurus has only been described from incomplete specimens, but it is known to have had a relatively elongate skull with specialised teeth.[1] By comparison with Dolichosaurus, it may have had four short limbs and an elongate neck and body. A maximum length between 0.5–1 m (1.6–3.3 ft) has been proposed.[3][4]

Phylogenetic analysis suggests that Coniasaurus is a sister group to the Mosasauroidea within the clade Pythonomorpha.[5]

References

edit
  1. ^ a b c Shimada K. & Bell G.L.Jr (2006). "Coniasaurus Owen, 1850 (Reptilia: Squamata), from the Upper Cretaceous Niobrara Chalk of western Kansas". Journal of Paleontology. 80 (3): 589–593. doi:10.1666/0022-3360(2006)80[589:corsft]2.0.co;2.[permanent dead link]
  2. ^ Owen, R. (1850). Descriptions of the fossils of the Chalk Formation. Description of the fossil reptiles of the Chalk Formation. The Geology and Fossils of the Tertiary and Cretaceous Formations of Sussex 378-404
  3. ^ a b Caldwell M.W. & Cooper J.A. (1999). "Redescription, palaeobiogeography and palaeoecology of Coniasaurus crassidens Owen, 1850 (Squamata) from the Lower Chalk (Cretaceous; Cenomanian) of SE England" (PDF). Zoological Journal of the Linnean Society. 127 (4): 423–452. doi:10.1111/j.1096-3642.1999.tb01380.x.
  4. ^ Bardet, Nathalie (2008). "The Cenomanian-Turonian (late Cretaceous) radiation of marine squamates (Reptilia): the role of the Mediterranean Tethys". Bulletin de la Société Géologique de France. 179 (6): 605–623. doi:10.2113/gssgfbull.179.6.605.
  5. ^ Caldwell M.A. (1999). "Squamate phylogeny and the relationships of snakes and mosasauroids" (PDF). Zoological Journal of the Linnean Society. 125 (1): 115–147. doi:10.1111/j.1096-3642.1999.tb00587.x.