Coniasaurus

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 PreꞒ Ꞓ O S D C P T J K Pg N
C. crassidens holotype, drawn by James Erxleben in 1850
Scientific 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]