[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryotes see Domain Eukaryota Chatton, 1925
     Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758
       Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
         Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
           Phylum Chordata Bateson, 1885 - chordates
             Subphylum Vertebrata Cuvier, 1812 - vertebrates
               Class "Agnatha" Cope, 1889
                 1 Subclass Myxinoidea - hagfishes
                 2.1 Subclass Petromyzontida - lampreys
                 2.2.1 Subclass †Conodonta Eichenberg, 1930 see Class Conodonta Eichenberg, 1930
                 2.2.2.1 Subclass †Pteraspidomorphi Goodrich, 1909 see Class Pteraspidomorphi Goodrich, 1909
                 2.2.2.2.1 Order †Anaspida Traquair - anaspids see Class Anaspida Traquair
                 2.2.2.2.2.1 Order †Thelodonti Jaekel, 1911 see Class Thelodonti Jaekel, 1911
                 2.2.2.2.2.2.1 Subclass †unnamed see Class Cephalaspidomorphi Moy-Thomas & Mile, 1971