Dolichosaurs may have occupied a niche similar to the earlier nothosaurs and modern sea snakes, in using their thin heads to feed in crevices and narrow spaces along coral reefs and rocky shores.

[9] Both of the genera routinely referred to the Dolichosauridae, Dolichosaurus and Coniasaurus, were described by Richard Owen in 1850 based on specimens of Cenomanian age collected from the Lower Chalk of southeastern England.

[10] The unusually large number of dorsal and cervical vertebrae present in Dolichosaurus prompted it to be named as a new genus and Coniasaurus could be distinguished from known Cretaceous lizards by dental characteristics.

[12] The difficulties in establishing more certain relationships not only between the Dolichosauridae and the Mosasauroidea, but also between Dolichosaurus and Coniasaurus, arise from the nature of the fossil remains referred to the genera.

[5] Cladogram following Augusta et al. (2022):[5] Ophidia (snakes) Varanoidea Primitivus Eidolosaurus Aphanizocnemus Dolichosaurus Pontosaurus Adriosaurus Acteosaurus Mosasauroidea