Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct.
       Infraphylum Vertebrata Lamarck, 1801 - vertebrates
         Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates
           Eugnathostomata
             Grade Chondrichthyomorphi [monotypic]
               Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
                 Subclass Holocephali Bonaparte, 1832
                   1 Family †Harpacanthidae Lund & Grogan, 2004
                   2 Family †Gregoriidae Lund & Grogan, 2004
                   3 [stem] Order †Iniopterygiformes Zangerl & Case, 1973
                   4 [stem] Order †Orodontiformes Zangerl, 1981
                   5 [stem] Order †Eugeneodontiformes Zangerl, 1981
                   6 [stem] Order †Petalodontiformes Zangerl, 1981
                   7 [stem] Order †Debeeriiformes Grogan & Lund, 2000 [monotypic]
                   8 [stem] Order †Helodontiformes Patterson, 1965 [monotypic]
                   9 Superorder Holocephalimorpha Lund, 1986