Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct.
       Vertebrata Lamarck, 1801 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
         Myopterygii Janvier, 1978 - myopterygians
           Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates
             Grade Chondrichthiomorphi see Grade Chondrichthyomorphi
               Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
                 Subclass Elasmobranchii Bonaparte, 1838 - shark-like fishes see Infraclass Elasmobranchii Bonaparte, 1838
                   Infraclass †Xenacanthimorpha see Superorder Xenacanthimorpha
                     1 ?Order †Omalodontiformes Turner, 1997
                     2.1 ?Genus †Antarctilamna Young, 1982
                     2.2 ?Genus †Wellerodus Turner, 1997
                     3 ?Genus †Diplodus Binney, 1841, nom. illeg. see Genus Didymodus Cope, 1883
                     4.1 ?Genus †Bransonella Harlton, 1933
                     4.2 ?Genus †Jalodus Ginter, 1999
                     4.3 ?Order †Phoebodontiformes Ginter, Hairapetian & Klug, 2002
                     5 Order †Xenacanthiformes Berg, 1955