†Placodermi McCoy, 1848
   †Arthrodira Woodward, 1891
     †Brachythoraci Gross, 1932
       †Eubrachythoraci Miles, 1971
         †Pachyosteomorphi Stensiö, 1944 - pachyosteomorphs
           Superfamily †Dunkleosteoidea Stensiö, 1963
             Family †Dunkleosteidae Stensiö, 1963, "nom. praeval."
               Genus †Hussakofia Cossmann, 1910 [monotypic]
                 1 †Hussakofia minor (Newberry, 1878)