Pliosaurus (meaning 'more lizard') is an extinctgenus of thalassophoneanpliosaurid known from the Late Jurassic (Kimmeridgian and Tithonian stages) of Europe and South America. This genus has contained many species in the past but recent reviews found only six (P. brachydeirus (type species), P. carpenteri, P. funkei, P. kevani, P. rossicus and P. westburyensis) to be definitively valid. One Patagonian species P. patagonicus likely belongs to a different genus within Brachaucheninae. Currently, P. brachyspondylus and P. macromerus are considered dubious, while P. portentificus is considered undiagnostic. Most European species of Pliosaurus would have measured around 10 metres (33 ft) long and weighed over 12 metric tons (13 short tons), though some potential specimens indicate a much larger size. Species of this genus are differentiated from other pliosaurids based on seven autapomorphies, including teeth that are triangular in cross section. Their diet would have included fish, cephalopods, and marine reptiles.
^José P. O'Gorman; Zulma Gasparini; Luis A. Spalletti (2018). "A new Pliosaurus species (Sauropterygia, Plesiosauria) from the Upper Jurassic of Patagonia: new insights on the Tithonian morphological disparity of mandibular symphyseal morphology". Journal of Paleontology. 92 (2): 240–253. Bibcode:2018JPal...92..240O. doi:10.1017/jpa.2017.82. hdl:11336/81697. S2CID134813424.
^Gasparini, Z.; O'Gorman, J. (2014). "A new species of Pliosaurus (Sauropterygia, Plesiosauria) from the Upper Jurassic of northwestern Patagonia, Argentina". Ameghiniana. 51 (4): 269–283. doi:10.5710/amgh.03.04.2014.2225. hdl:11336/9372. S2CID130194647.