Vertebrata Cuvier, 1812 - vertebrates
   Gnathostomata
     Teleostomi
       Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988]
         Amniota Haeckel, 1866 [Gauthier, Kluge & Rowe 1988] - amniotes
           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 Lepidosauria Haeckel, 1866 see Superorder Lepidosauriformes Gauthier, Estes & de Queiroz, 1988
                   Order Squamata Oppel, 1811
                     Suborder Serpentes Linnaeus, 1758 - snakes
                       Infraorder Caenophidia Hoffstetter, 1939 see Superfamily Xenophidia
                         Superfamily Colubroidea Oppel, 1811
                           1 Family Anomalopheidae see Family Anomalophiidae Auffenberg, 1959
                           2 Family Russellopheidae Rage, 1978 see Family Russellophiidae Rage, 1975
                           3 Family Colubridae Oppel, 1811 - colubrids
                           4 Family Elapidae Boie, 1827
                           5 Family Viperidae Oppel, 1811 - vipers and pit vipers