''Dolichosaurus'' (meaning "long lizard") 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 ...

of marine

squamate 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 ...

of the Upper Cretaceous Cenomanian chalk deposits of England. Sister-group relationships between coniasaurs, dolichosaurs,

Aigialosauridae Aigialosauridae (from Greek, ''aigialos'' = "seashore" and ''sauros''= lizard) is a family of Late Cretaceous semiaquatic pythonomorph lizards closely related to the mosasaurs. Regarded by some paleontologists as a distinct monophyletic group ...

and Mosasauridae are an unresolved

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

. The paleobiology of ''Dolichosaurus'' is reconstructed as similar to coniasaurs,

nothosaurs Nothosaurs (order Nothosauroidea) were Triassic marine sauropterygian reptiles that may have lived like pinniped, seals of today, catching food in water but coming ashore on rocks and beaches. They averaged about in length, with a long body and ...

, and modern

sea snakes Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, wher ...

.Michael W. Caldwell
On the aquatic squamate ''Dolichosaurus longicollis'' Owen, 1850 (Cenomanian, Upper Cretaceous), and the evolution of elongate necks in squamates
''Journal of Vertebrate Paleontology'' 20(4):720-735. 2000. doi: https://dx.doi.org/10.1671/0272-4634(2000)020 720:OTASDL.0.CO;2

References

Cretaceous lizards Late Cretaceous lepidosaurs of Europe Fossil taxa described in 1850 Taxa named by Richard Owen Prehistoric squamates Prehistoric reptile genera {{paleo-lizard-stub