"s. popularis" was about 15 metres (50 ft) long. a longer specimen is now placed in "shastasaurus" rather than "shonisaurus". "shonisaurus" had a long pointed mouth that contained teeth only at the front end. it had a large whale-like body, a long dolphin-like snout, and its flippers were much longer, and narrower than in other ichthyosaurs. all of these features suggest that "shonisaurus" may be a relatively specialised offshoot of the main ichthyosaur evolutionary line.