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 see Infraphylum Vertebrata Lamarck, 1801
          Count: [f] 7c;109o;885f;3075g;781s;13ss; ‡1f;6g;7s;1ss; †1c;3o;2f;1g
             Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
            Count: 29o;178f;600g;61s; ‡1f;5g;5s; †3o;2f;1g
               Subclass Neornithes Gadow, 1893 see Clade Neornithes Gadow, 1893
              Count: [f] 29o;178f;600g;61s; ‡1f;5g;5s; †3o;2f
                 Superorder Palaeognathae Pycraft, 1900 see Cohort Palaeognathae Pycraft, 1900
                Count: [f] 5o;6f;11g;7s; ‡1s; †1o;2f
                   Order Rheiformes Forbes, 1884 see Suborder Rheae Forbes, 1884
                  Count: [*] 1f;2g;2s
                     Family Rheidae Bonaparte, 1849 - rheas
                    Count: [*] 2g;2s
                       1 Genus Rhea Brisson, 1760
                      Count: [*] 1s
                       2 Genus Pterocnemia Gray, 1871
                      Count: [*] 1s