Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Pisces
       Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
         Subclass Elasmobranchii Bonaparte, 1838 - shark-like fishes
           Order †Cladoselachiformes
           Order †Ctenacanthiformes Glikman, 1964
           Order †Symmoriida Zangerl, 1981
           Order †Xenacanthiformes Berg, 1955