''Dolichosaurus'' (meaning "long lizard") is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of marine

squamate Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it i ...

of the Upper Cretaceous

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

chalk deposits of England. It is a member of the family

Dolichosauridae Dolichosauridae (from Latin, ''dolichos'' = "long" and Ancient Greek, Greek ''sauros''= lizard) is a family of Cretaceous Aquatic animal, aquatic lizards. They are widely considered to be the earliest and most primitive members of Mosasauria, tho ...

.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 It was a small reptile measuring long. It had an elongate neck resulting from an increased number of cervical vertebrae.

References

Dolichosauridae 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