Shonisaurus

Shonisaurus was the largest genus of ichthyosaur that has yet been found. Fossils of Shonisaurus were first found in a large deposit in Nevada in 1920. Thirty years later, they were excavated and it was found that the deposit contained the remains of 37 very large icthyosaurs which were named Shonisaurus, which means "Lizard from the Shoshone Mountains", after the formation where the fossils were found.

Shonisaurus lived during the Norian stage of the Late Triassic period. It had a whale-like body and long narrow paddles. Shonisaurus had a long pointed mouth that contained teeth only at the front end.

The first species discovered, S. popularis, was adopted as the State Fossil of Nevada in 1984. Excavations, begun in 1954 under the direction of Dr. Charles Camp and Dr. Samuel Welles of the University of California, Berkeley, were continued by Camp throughout the 60s. It was named by Charles Camp in 1976.

Shonisaurus popularis specimens reached a length of 15 meters (50 feet). The Nevada fossil sites can currently be viewed at the Berlin-Ichthyosaur State Park.

A discovery in British Columbia in the 1990s made S. popularis the smaller of the Shonisaurus species; a second species, S. sikanniensis, was discovered and has an estimated length of 21 meters (70 feet).

An ichthyosaur found in the Himalayan mountains called Himalayasaurus, may be the same animal as Shonisaurus.