Phylum [Vertebrata] (Lamarck, 1801)
   Class †Placodermi McCoy, 1848
     Order †Arthrodira Woodward, 1891 see Order Arthrodiriformes Grande & Eastman, 1986
       1 Genus †Coccosteus Miller, 1841
       2 Genus †Dunkleosteus Lehman, 1956
       3 Genus †Groenlandaspis Heintz, 1932