Temporal range: Late Triassic
|A restoration of Shonisaurus popularis|
| †Shonisaurus popularis|
Shonisaurs thrived during the Late Triassic Period and were among the first Ichthyosaurs, as well as the largest, though their relative Shastasaurus was probably even bigger. The diet of these ichthyosaurs probably consisted of fish, ammonites, and smaller marine reptiles.
Shonisaurus reached around 48 feet in total body length and fed on fish, squids, and smaller marine reptiles. They lived throughout the Triassic Period in the seas that covered what is now the state of Nevada in the United States of America.