Phylum [Vertebrata] Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801
   Class †Placodermi McCoy, 1848
     1 Order †Rhenanida Broili, 1930
     2 Order †Ptyctodontida Gross, 1932 see Order Ptyctodontiformes
     3 Order †Arthrodira Woodward, 1891 see [unranked] Arthrodira Woodward, 1891
     4 Order †Antiarchi Cope, 1885 see [unranked] Antiarchi Cope, 1885
     5 Genus †Palaeospondylus Traquair, 1890