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
             Order †Ichthyopterygia Blainville, 1835 [coordinate rank]
               1 ?Family †Hupehsuchidae [monotypic]
               2 Family †Utatsusauridae Carroll, 1988, nom. nud. [monotypic] see Family Utatsusauridae McGowan & Motani, 2003
               3 Family †Omphalosauridae Merriam, 1906
               4 Family †Mixosauridae Baur, 1887 [monotypic]
               5 Family †Shastasauridae Merriam, 1902
               6 Family †Ichthyosauridae Bonaparte, 1841
               7 Family †Stenopterygiidae Kühn, 1934 [monotypic]
               8 Family †Protoichthyosauridae Appleby, 1979 [monotypic]
               9 Family †Leptopterygiidae Kuhn, 1934