Phylum [Vertebrata] Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801
   Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
     Subclass Elasmobranchii Bonaparte, 1838 - shark-like fishes see Infraclass Elasmobranchii Bonaparte, 1838
       Order †Euselachii Hay, 1902 see Subclass Euselachii Hay, 1902
         1 Genus †Hybodus Agassiz, 1834
         2 Genus †Tristychius Agassiz, 1837