Wikipedia
Thalattosaurus (pron.:"tha-la-to-SORE-us") meaning "ocean lizard" is an extinct genus of marine reptile in the family Thalattosauridae. They are aquatic diapsids that are known exclusively from the Triassic period, and have recently gained attention as a result of studies on general diapsid phylogeny.
Thalattosaurus was a shellfish-eating reptile around 2 meters (7 ft) in length occurring in the Lower and Middle of British Columbia as well as Upper Triassic of California.
Although originally described as four distinct species by Merriam in 1905, one was proven to be T. alexandrae upon further inspection and another has a missing type specimen. Currently it is believed to include two known species; Thalattosauridae alexandrae and Thalattosauridae borealis.
Both species have paddle-like limbs and a down-turned rostrum.