Named By: Harry Govier Seeley - 1873.
Classification: Chordata, Reptilia, Ichthyosauria, Thunnosauria.
Species: C. walkeri (type).
Size: Unknown due to lack of remains.
Known locations: England - West Melbury Marly Chalk Formation.
Time period: Albian/Cenomanian of the Cretaceous.
Fossil representation: Fragmentary post cranial remains.
Cetarthrosaurus is a little known and often considered dubious genus of ichthyosaur that is only known from fragmentary post cranial remains. Still, Cetarthrosaurus is identified as a thunnosaurian ichthyosaur that was hunting in the waters around what would become England around the boundary of the early and late Cretaceous. Fossil remains of ichthyosaurs disappear from the fossil record not long after the end of the Cenomanian when an anoxic event caused a mass extinction of marine life. With this in mind, Cetarthrosaurus would have possibly been among the last ichthyosaurs to live.
- On Cetarthrosaurus walkeri (Seeley), an Ichthyosaurian from the Cambridge Upper Greensand. - Quarterly Journal of the Geological Society 29: 505–507. - Harry Govier Seeley - 1873.
- High Diversity in Cretaceous Ichthyosaurs from Europe Prior to Their Extinction. - PLoS ONE 9: e84709. - Valentin Fischer, Nathalie Bardet, Myette Guiomar & Pascal Godefroit. - 2014.