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 †Ichthyopterygia Blainville, 1835 [monotypic] - ichthyopterygians
                 Order †Ichthyosauria Blainville, 1835
                   Suborder †Longipinnati (Huene, 1948)
                     Family †Stenopterygiidae (Kühn, 1934)
                       Genus †Stenopterygius Jaekel, 1904
                         1 †Stenopterygius quadriscissus (Quenstedt, 1858)