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 Euselachii Hay, 1902 - sharks and rays, and related fossils see Subclass Euselachii Hay, 1902
                     Division Neoselachii Compagno, 1977 see Infraclass Elasmobranchii Bonaparte, 1838
                       Subdivision Selachii - sharks see Division Selachii
                         Superorder Galeomorphi Compagno, 1973
                           Order Heterodontiformes Compagno, 1973 [monotypic] - bullhead sharks
                             1 Family Heterodontidae Gray, 1851 [monotypic] - bullhead sharks