Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct.
       Vertebrata Lamarck, 1801 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
         Myopterygii Janvier, 1978 - myopterygians
           Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates
             Grade †Placodermiomorphi [monotypic]
               Class †Placodermi McCoy, 1848
                 Order †Arthrodiriformes Grande & Eastman, 1986 - arthrodires see [unranked] Arthrodira Woodward, 1891
                   Suborder †Phlyctaeniida see Suborder Phlyctaenioidei
                     1 Family †Phlyctaeniidae Fowler, 1947 (1929)
                     2 Family †Groenlandaspididae Obruchev, 1964, orth. inval. see Family Gronlandaspididae Obruchev, 1964