Opinions from F. R. O'Keefe 2001
- 'Alzadasaurus colombiensis is recombined as Callawayasaurus colombiensis'
- 'Attenborosaurus belongs to Pliosauroidea'
- 'Augustasaurus belongs to Pistosauridae'
- 'Augustasaurus hagdorni belongs to Augustasaurus' according to Sander et al. 1997
- 'Augustasaurus hagdorni belongs to Augustasaurus'
- 'Brachauchenius belongs to Pliosauridae'
- 'Brachauchenius lucasi belongs to Brachauchenius' according to Williston 1903
- 'Brachauchenius lucasi belongs to Brachauchenius'
- 'Brancasaurus belongs to Elasmosauridae'
- 'Brancasaurus brancai belongs to Brancasaurus'
- 'Callawayasaurus belongs to Elasmosauridae'
- 'Cimoliasauridae belongs to Tricleidia'
- 'Cimoliosaurus snowii is recombined as Styxosaurus snowii' according to Welles 1943
- 'Cimoliosaurus snowii is recombined as Styxosaurus snowii'
- 'Cryptocleidoidea belongs to Euplesiosauria'
- 'Cryptoclididae belongs to Cryptocleidoidea'
- 'Cymatosaurus belongs to Pistosauria'
- 'Cymatosaurus fridericianus belongs to Cymatosaurus' according to Frtisch 1894
- 'Cymatosaurus fridericianus belongs to Cymatosaurus'
- 'Dolichorhynchops belongs to Polycotylidae'
- 'Dolichorhynchops osborni belongs to Dolichorhynchops'
- 'Elasmosauridae belongs to Euplesiosauria'
- 'Elasmosaurus morgani is recombined as Libonectes morgani'
- 'Eosauropterygia belongs to Sauropterygia'
- 'Euplesiosauria belongs to Plesiosauroidea'
- 'Eurycleidus belongs to Pliosauroidea'
- 'Hauffiosaurus belongs to Pliosauridae'
- 'Hauffiosaurus zanoni belongs to Hauffiosaurus'
- 'Kimmerosaurus belongs to Cimoliasauridae'
- 'Kimmerosaurus langhami belongs to Kimmerosaurus'
- 'Kronosaurus belongs to Pliosauridae'
- 'Kronosaurus queenslandicus belongs to Kronosaurus'
- 'Leptocleidus belongs to Rhomaleosauridae'
- 'Libonectes belongs to Elasmosauridae'
- 'Liopleurodon belongs to Pliosauridae'
- 'Liopleurodon ferox belongs to Liopleurodon' according to Sauvage 1873
- 'Liopleurodon ferox belongs to Liopleurodon'
- 'Macroplata belongs to Pliosauridae'
- 'Macroplata tenuiceps belongs to Macroplata'
- 'Microcleidus belongs to Euplesiosauria'
- 'Morturneria belongs to Cimoliasauridae'
- 'Muraenosaurus belongs to Cryptoclididae'
- 'Muraenosaurus (Cryptoclidus) was reranked as Cryptoclidus and belongs to Cryptoclididae'
- 'Muraenosaurus leedsii belongs to Muraenosaurus'
- 'Peloneustes belongs to Pliosauridae'
- 'Pistosauria was reranked as a unranked clade and belongs to Sauropterygia'
- 'Pistosauridae belongs to Pistosauria'
- 'Pistosaurus belongs to Pistosauridae'
- 'Pistosaurus grandaevus belongs to Pistosaurus' according to Meyer 1839
- 'Pistosaurus longaevus belongs to Pistosaurus'
- 'Placodontia belongs to Sauropterygia'
- 'Plesiosauria belongs to Pistosauria'
- 'Plesiosauroidea belongs to Plesiosauria'
- 'Plesiosaurus belongs to Plesiosauroidea'
- 'Plesiosaurus (Pleiosaurus) brachydeirus is recombined as Pliosaurus brachydeirus'
- 'Plesiosaurus (Thaumatosaurus) victor is recombined as Thaumatosaurus victor' according to Fraas 1920
- 'Plesiosaurus (Thaumatosaurus) victor is recombined as Rhomaleosaurus victor'
- 'Plesiosaurus arcuatus is recombined as Eurycleidus arcuatus'
- 'Plesiosaurus brachypterygius belongs to Plesiosaurus'
- 'Plesiosaurus capensis is recombined as Leptocleidus capensis'
- 'Plesiosaurus conybeari is recombined as Attenborosaurus conybeari'
- 'Plesiosaurus cramptoni is recombined as Rhomaleosaurus cramptoni' according to Seeley 1874
- 'Plesiosaurus cramptoni is recombined as Rhomaleosaurus cramptoni'
- 'Plesiosaurus dolichodeirus belongs to Plesiosaurus' according to Conybeare 1824
- 'Plesiosaurus dolichodeirus belongs to Plesiosaurus'
- 'Plesiosaurus eurymerus is recombined as Cryptoclidus eurymerus'
- 'Plesiosaurus guilelmiimperatoris belongs to Plesiosaurus'
- 'Plesiosaurus hawkinsii is recombined as Thalassiodracon hawkinsi'
- 'Plesiosaurus homalospondylus is recombined as Microcleidus homalospondylus'
- 'Plesiosaurus longirostris belongs to Plesiosaurus' according to Blake 1876
- 'Plesiosaurus longirostris is recombined as Macroplata longirostris'
- 'Plesiosaurus megacephalus belongs to Plesiosaurus' according to Stutchbury 1846
- 'Plesiosaurus megacephalus is recombined as Rhomaleosaurus megacephalus'
- 'Plesiosaurus philarchus is recombined as Peloneustes philarchus'
- 'Plesiosaurus zetlandicus is recombined as Rhomaleosaurus zetlandicus' according to Phillips 1854
- 'Plesiosaurus zetlandicus is recombined as Rhomaleosaurus zetlandicus'
- 'Pliosauridae belongs to Pliosauroidea'
- 'Pliosauroidea belongs to Plesiosauria'
- 'Polycotylidae belongs to Tricleidia'
- 'Polycotylus belongs to Polycotylidae'
- 'Polycotylus latipinnis belongs to Polycotylus'
- 'Rhomaleosauridae belongs to Pliosauroidea'
- 'Rhomaleosaurus belongs to Rhomaleosauridae'
- 'Simolestes belongs to Rhomaleosauridae'
- 'Simolestes vorax belongs to Simolestes' according to Andrews 1909
- 'Simolestes vorax belongs to Simolestes'
- 'Simosaurus gaillardoti belongs to Simosaurus'
- 'Styxosaurus belongs to Elasmosauridae'
- 'Thalassiodracon belongs to Plesiosauria'
- 'Tricleidia belongs to Cryptocleidoidea'
- 'Tricleidus belongs to Tricleidia'
- 'Tricleidus seeleyi belongs to Tricleidus' according to Andrews 1909
- 'Tricleidus seeleyi belongs to Tricleidus'
- 'Trinacromerum belongs to Polycotylidae'
- 'Trinacromerum bentonianum belongs to Trinacromerum' according to Cragin 1888
- 'Trinacromerum bentonianum belongs to Trinacromerum'
- 'Turneria seymouriensis is recombined as Morturneria seymourensis'