Cryptocleidus was a plesiosaur, a type of marine reptile. It was not a dinosaur, though it coexisted with many dinosaurs. The first Cryptocleidus fossil was discovered in 1892.

All the Cryptocleidus illustrations below were collected from the internet. Enjoy and explore:

Cryptocleidus was described by the following scientific paper(s):
  • D. M. Martill. 1986. The stratigraphic distribution and preservation of fossil vertebrates in the Oxford Clay of England. Mercian Geologist 10(3):161-186
  • D. Martill. 1984. The occurrence of a dinosaurian phalanx in the Lower Oxford Clay of Peterborough, Cambridge. Mercian Geologist 9(4):209-211
  • D. S. Brown. 1981. The English Upper Jurassic Plesiosauroidea (Reptilia) and a review of the phylogeny and classification of the Plesiosauria. Bulletin of the British Museum (Natural History) 35(4):253-347