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