Cimoliasaurus was a plesiosaur that lived during the Late Cretaceous (Maastrichtian) of New Jersey.
The name is derived from the Greek Greek, Ancient (to 1453);: Κιμωλία Greek, Ancient (to 1453);: kimolia, meaning "white chalk", and Greek, Ancient (to 1453);: σαύρος Greek, Ancient (to 1453);: sauros, meaning "lizard", in reference to the fact that the deposits in which it was found bear a superficial resemblance to the chalk deposits of the Western Interior Seaway.
The name Cimoliasaurus magnus was coined by Joseph Leidy for ANSP 9235, one anterior and 12 posterior cervical vertebrae collected in Maastrichtian-aged greensand deposits in Burlington County, New Jersey.[1]
In his catalogue of plesiosaur and ichthyosaur specimens preserved in the NHM, the British zoologist Richard Lydekker referred several Jurassic and Cretaceous plesiosaur species to Cimoliasaurus, including the new species C. richardsoni (now considered a species of Cryptoclidus) and C. cantabrigiensis, as well as Colymbosaurus and a number of previously described species from the Cambridge Greensand and Chalk Group.[2]
Nowadays, Cimoliasaurus is now recognized as being a derived elasmosaurid, effectively making the family name Cimoliasauridae Delair, 1959 a junior synonym of Elasmosauridae.[3]