living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Hemichordata Bateson, 1885 - hemichordates
           Class Pterobranchia Lankester, 1877 - pterobranchs
             Family Cephalodiscidae Schimkewitsch, 1893
               Genus Cephalodiscus M'Intosh, 1882
                 01 Cephalodiscus sibogae Harmer, 1905
                 02 Cephalodiscus dodecalophus McIntosh, 1882
                 03 Cephalodiscus indicus Schepotieff, 1909
                 04 Cephalodiscus evansi Ridewood
                 05 Cephalodiscus nigrescens Lankester, 1905
                 06 Cephalodiscus hodgsoni Ridewood, 1907
                 07 Subgenus Orthoecus
                 08 Subgenus Idiothecia
                 09 Subgenus Demiothecia
                 10 Subgenus Acoelothecia