Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Class Reptilia Linnaeus, 1758 - reptiles
               Subclass †Euryapsida Colbert, 1945 see Subclass Diapsida Osborn, 1903
                 Order †Sauropterygia Owen, 1860 see Superorder Sauropterygia Owen, 1860
                   Suborder †Plesiosauria Blainville, 1835 see Order Plesiosauria Blainville, 1835
                     1 Family †Pistosauridae Zittel, 1887
                     2 Family †Pliosauridae Seeley, 1874
                     3 Family †Polycotylidae Williston, 1908
                     4 Family †Plesiosauridae Gray, 1825
                     5 Family †Elasmosauridae Cope, 1869