What is "largocephalosaurus"

Largocephalosaurus is an extinct genus of basal saurosphargid, a marine reptile known from the Middle Triassic ( Anisian age) Guanling Formation of Yunnan and Guizhou Provinces, southwestern China. It contains a type species, Largocephalosaurus polycarpon, and a second species L. qianensis.

L. polycarpon was initially interpreted as an eosauropterygian sauropterygian closely related to European pachypleurosaurs and nothosaurids. However following additional preparation of the postcranial skeleton and the discovery of a second better known species L. qianensis, Li et al. (2014) reinterpreted Largocephalosaurus as a basal member of the family Saurosphargidae and a close relative of Saurosphargis and Sinosaurosphargis. According to Li et al. (2014), saurosphargids did not belong to Sauropterygia, although they were closely related to it, forming its sister taxon.