living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
Count: 4k;54p;156c;911o;7123f;17,575g;4762s;36ss;8v;19; ‡1f;6g;7s;1ss; †1c;10o;10f;19g;1s
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
  Count: [c] 2k;51p;154c;900o;7001f;17,209g;4300s;33ss;8v; ‡1f;6g;7s;1ss; †1c;10o;10f;19g;1s
     Kingdom Animalia Linnaeus, 1758 - animals
    Count: [c] 38p;101c;595o;5766f;13,419g;3233s;32ss;3v; ‡1f;6g;7s;1ss; †1c;9o;10f;16g;1s
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
      Count: [c] 29p;70c;458o;5094f;11,476g;2933s;31ss;3v; ‡1f;6g;7s;1ss; †1c;8o;10f;11g;1s
         Phylum Chordata Bateson, 1885 - chordates
        Count: [o] 10c;115o;905f;3134g;786s;13ss; ‡1f;6g;7s;1ss; †1c;3o;2f;1g
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
          Count: [f] 7c;109o;885f;3075g;781s;13ss; ‡1f;6g;7s;1ss; †1c;3o;2f;1g
             Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
            Count: 14o;51f;133g;15s
               Subclass Elasmobranchii Bonaparte, 1838 - shark-like fishes
              Count: [f] 13o;48f;127g;14s
                 Cohort Euselachii Hay, 1902 - spined sharks and relatives see Infraclass Euselachii Hay, 1902
                Count: [f] 13o;48f;127g;14s
                   Subcohort Neoselachii Compagno, 1977 - modern sharks and rays see Cohort Neoselachii Compagno, 1977
                  Count: [f] 13o;48f;127g;14s
                     Superorder Galeomorphii Compagno, 1973 see Division Galeomorphii Compagno, 1973
                    Count: [g] 4o;23f;67g;1s
                       Order Heterodontiformes Compagno, 1973 - bullhead sharks
                      Count: 1f;1g
                         1 Family Heterodontidae Gray, 1851 - bullhead and horn sharks
                        Count: [g] 1g