Temporal range: Upper Triassic, 216–218 mya
Californosaurus lived during the late Triassic period in seas that covered what is now California. It fed on fish and other small marine creatures. Like other ichthyosaurs it probably never came onto dry land, and gave birth in the water.
It is the most basal known true ichthyosaur, shaped more or less like a dolphin. The long-snouted head is small in comparison with the rest of the body, as in basal ichthyosaurs such as Mixosaurus and Cymbospondylus. The tail is sharply turned downwards, in common with more advanced ichthyosaurs, with a small vertical fluke. It may have had a small dorsal fin.