Phylum [Vertebrata] (Lamarck, 1801)
   Class Reptilia Linnaeus, 1758 - reptiles
     Subclass Diapsida Osborn, 1903 - diapsids see Clade Diapsida Osborn 1903 [Gauthier & de Queiroz 2020]
       Order †Choristodera Cope, 1876
         1 Family †Champsosauridae Cope, 1884