Vertebrata Cuvier, 1812 - vertebrates
 see Infraphylum Vertebrata Lamarck, 1801
  
 Gnathostomata
    
 Teleostomi Bonaparte, 1836
      
 Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988], nom. cl. inval.
 see Clade Tetrapoda Hatschek & Cori 1896 [Laurin 2020]
        
 Amniota Haeckel, 1866 [Gauthier, Kluge & Rowe 1988], nom. cl. inval. - amniotes
 see Clade Amniota Haeckel 1866 [Laurin & Reisz 2020]
          
 Class Reptilia Linnaeus, 1758 [paraphyletic] - reptiles
            
 Subclass Diapsida Osborn, 1903 - diapsids
 see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
              
 Infraclass Lepidosauromorpha Benton, 1983
 see Subclass Lepidosauromorpha Benton, 1983
                
 Superorder †Sauropterygia Owen, 1860
                  
 Order †Plesiosauria Blainville, 1835 - plesiosaurs
                    
 Superfamily †Pliosauroidea Welles, 1943 [monotypic]
 see Suborder Pliosauroidea Welles, 1943
                      
 Family †Pliosauridae Seeley, 1874
                        
 Genus †Rhomaleosaurus Seeley, 1874