''Coniasaurus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

marine

squamates Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species, it ...

that range in age from Cenomanian to Santonian. It was first described by Richard Owen in 1850 from lower Cenomanian

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...

deposits in southeast England ( Sussex). Two species have been described from this genus: ''C. crassidens'' (Owen, 1850), known from Cenomanian to Santonian deposits from southeast

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

and North America, and ''C. gracilodens'' (Caldwell, 1999) from the Cenomanian of southeast

. ''Coniasaurus'' has only been described from incomplete specimens, but it is known to have had a relatively elongate skull with specialised teeth. By comparison with ''

Dolichosaurus ''Dolichosaurus'' (meaning "long lizard") is an extinct genus of marine squamate of the Upper Cretaceous Cenomanian chalk deposits of England. Sister-group relationships between coniasaurs, dolichosaurs, Aigialosauridae and Mosasauridae are ...

'', it may have had four short limbs and an elongate neck and body. A maximum length between has been proposed.

Phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

suggests that ''Coniasaurus'' is a sister group to the Mosasauroidea within the clade Pythonomorpha.

References

{{Taxonbar, from=Q3686975 Prehistoric squamates Prehistoric reptile genera Cretaceous lizards Late Cretaceous lepidosaurs of Europe