Pachypleurosauria
Classification
Sauropterygia--> Eosauropterygia--> Pachypleurosauria
The Pachypleurosauria is an exclusively Middle Triassic group of semi-aquatic sauropterygians. They were once regarded as a type of 'nothosaur' but traditional concept of "Nothosauria" is no longer in use, as it was paraphyletic group containing two lineages. The more 'primitive' of these is the pachypleurosauria, whereas the more derived members form a separate clade of common ancestry, today referred to as the "Nothosauria" under a revised definition (Rieppel, 1998). Pachypleurosaur genera include: Anarasaurus Dactylosaurus Keichousaurus Neusticosaurus ('Pachypleurosaurus') 'Psilotrachelosaurus' Serpianosaurus
