Named By: Harry Govier Seeley - 1874.
Classification: Chordata, Reptilia, Sauropterygia, Plesiosauria, Plesiosauroidea.
Species: C. megadeirus, C. svalbardensis.
Type: Uncertain due to incomplete fossil material, but presumed to be a piscivore.
Size: Uncertain due to incomplete fossil materia.
Known locations: England, Dorset - Jurassic Coast, Kimmeridge Clay.
Time period: Kimmeridgian of the Jurassic.
Fossil representation: Only partial post cranial remains including vertebrae, ribs, limbs, and parts of the shoulder girdle.
Another plesiosaur named Kimmerosaurus is known from the Kimmeridge Clay, and interestingly while Colymbosaurus is known only from incomplete post cranial remains, Kimmerosaurus is known only from the skull and a few cervical vertebra. This has led to speculation that the two genera are actually one and the same species. However, only the more complete remains that fill in the gaps of either one would be enough to settle this with certainty.
- Note on some generic modifications of the plesiosaurian pectoral arch. - Quarterly Journal of the Geological Society of London 30:436-449. - H. G. Seeley - 1874.
- The English Upper Jurassic Plesiosauridea (Reptilia) and a review of the phylogeny and classification of the Plesiosauria. - Bulletin of the British Museum of Natural History. 35 (4): 253–347. - D. S. Brown - 1981.
- Anatomy of Colymbosaurus (Reptilia, Plesiosauria) from the Kimmeridge Clay Formation of the U.K., and high diversity among Late Jurassic plesiosauroids. - Journal of Vertebrate Paleontology 34(5), 1053-1071. - R. B. J. Benson & T. Bowdler - 2014.