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
             Superclass Pisces Linnaeus, 1758 - fishes
               Class †Placodermi McCoy, 1848
                 1 Order †Stensioellida Romer, 1945 see Order Stensioelliformes
                 2 Order †Pseudopetalichthyda see Order Pseudopetalichthyiformes
                 3 Order †Ptyctodontida Gross, 1932 see Order Ptyctodontiformes
                 4 Order †Rhenanida Broili, 1930 see Order Rhenaniformes
                 5 Order †Acanthothoraci Stensiö, 1944 see Order Acanthothoraciformes
                 6 Order †Petalichthyida Jaekel, 1911 see Order Petalichthyiformes
                 7 Order †Antiarchi Cope, 1885 see Order Antiarchiformes Grande & Eastman, 1986
                 8 Order †Phyllolepida Stensiö, 1934 see Suborder Phyllolepidoidei
                 9 Order †Arthrodira Woodward, 1891 see Order Arthrodiriformes Grande & Eastman, 1986