Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct. see Subphylum Vertebrata Cuvier, 1812
       Vertebrata (Lamarck, 1801) - vertebrates see Subphylum Vertebrata Cuvier, 1812
         Myopterygii - myopterygians
           Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates
             Grade Chondrichthiomorphi
               Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
                 Subclass Elasmobranchii Bonaparte, 1838 - shark-like fishes
                   Infraclass Euselachii Hay, 1902 - sharks and rays, and related fossils
                     Division Neoselachii Compagno, 1977
                       Subdivision Selachii - sharks
                         Superorder Squalomorphi
                           Order Squaliformes Compagno, 1973 - dogfish sharks
                             Family Somniosidae Jordan, 1888 - sleeper sharks
                               1 Genus Centroscymnus Bocage & Capello, 1864 - velvet dogfishes
                               2 Genus Centroselachus Garman, 1913 [monotypic]
                               3 Genus Proscymnodon Fowler, 1934
                               4 Genus Scymnodalatias Garrick, 1956
                               5 Genus Scymnodon Bocage & Capello, 1864 [monotypic] - velvet dogfishes
                               6 Genus Somniosus Lesueur, 1818
                               7 Genus Zameus Jordan & Fowler, 1903