Thalattosaurus

Thalattosaurus (pronounced: , from Ancient Greek: θάλαττα, romanized: thálatta, lit.'sea' and σαῦρος, saûros, 'lizard') is an extinctgenus of marine reptile in the familyThalattosauroidea. Known exclusively from the Triassicperiod, it was a 2–3 metres (6.6–9.8 ft) long shellfish-eating diapsid with paddle-like limbs and a down-turned rostrum. Fossils were recovered in the Lower and Middle Triassic Sulphur Mountain Formation of British Columbia as well as the Upper Triassic Hosselkus Limestone of California. It has gained notoriety as a result of studies on general diapsid phylogeny.

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; Thalattosaurus alexandrae and T. borealis.