[Phylum] Chordata Bateson, 1885 - chordates
   Subphylum Craniata auct.
     Infraphylum Vertebrata Lamarck, 1801 - vertebrates
       Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates
         Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
           Subclass Holocephali Bonaparte, 1832
             Order †Petalodontiformes Zangerl, 1981
               1 Family †Belantseidae Lund, 1989
               2 Family †Petalodontidae Newberry & Worthen, 1866
               3 Family †Pristodontidae Woodward, 1889
               4 Family †Janassidae Jaekel, 1898
               5 Family †Petalorhynchidae Lund, Grogan & Fath, 2014
               6 Family †Obruchevodidae Lund, Grogan & Fath, 2014