Mesosaurus

Mesosaurus
Temporal range: Early Permian
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Clade: Sauropsida
Order: †Mesosauria
Seeley, 1892
Family: †Mesosauridae
Baur, 1889
Genus: †Mesosaurus
Gervais, 1865
Species:
†M. tenuidens
Binomial name
†Mesosaurus tenuidens
Gervais, 1865
Synonyms
List
  • Mesosaurus brasiliensis McGregor, 1908
  • Ditrochosaurus capensis Gurich, 1889
  • Mesosaurus capensis (Gurich, 1889)
  • Brazilosaurus sanpauloensis Shikama & Ozaki, 1966
  • Stereosternum tumidum Cope, 1885
  • Mesosaurus tumidum Cope, 1885

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 around the shorelines of the Irati–Whitehill sea, an epicontinental sea that covered parts of southern Pangaea during the late Early Permian, likely feeding on small prey such as pygocephalomorph crustaceans. Mesosaurs have often been considered parareptiles, though the validity of "Parareptilia" has recently been brought into question. Recent studies regardless place mesosaurs as basal, non-diapsid reptiles.