organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
             Superclass Pisces Linnaeus, 1758 - fishes
               Class Cephalaspidomorphi Kiaer & Stensiö, 1920 see Class Osteostraci Lankester, 1868
                 1 Order †Anaspidiformes
                 2 Order Petromyzontiformes Berg, 1940 - lampreys
                 3 Order †Galeaspidiformes see Order Eugaleaspidiformes Pan, 1983
                 4 Order †Cephalaspidiformes Halstead Tarlo, 1967