مسوسورس

Mesosaurus (meaning "middle lizard") is an extinct genus of aquatic reptile from the late Early Permian (Kungurian, ~275 million years ago) of southern Africa and South America. It is the only member of the family Mesosauridae and order Mesosauria. Two other genera of mesosaurs, Brazilosaurus and Stereosternum, were formerly recognised, but are now considered synonyms of Mesosaurus. Mesosaurus contains a single valid species, M. tenuidens. Mesosaurus represents one of the earliest lineages of aquatically adapted reptiles. It had many adaptations to a fully aquatic lifestyle. Mesosaurus lived a