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 Testudinata Oppel, 1811 [monotypic] - testudinates
               Order Chelonia Brongniart, 1800 see Class Chelonia Brongniart, 1800
                 Suborder Cryptodira Cope, 1868
                   Superfamily Trionychoidea Gray, 1825
                     1 Family Kinosternidae Agassiz, 1857 - mud and musk turtles
                     2 Family Dermatemydidae Gray, 1870 - Mesoamerican river turtles
                     3 Family Carettochelyidae Boulenger, 1887 - pignose turtles
                     4 Family Trionychidae Gray, 1825 - softshell turtles