Vertebrata Cuvier, 1812 - vertebrates Gnathostomata Class †Placodermi McCoy, 1848 Order †Arthrodira Woodward, 1891 see Order Arthrodiriformes Grande & Eastman, 1986 Suborder †Brachythoraci Gross, 1932 Superfamily †Homosteoidea Denison, 1978 [monotypic] 1 Family †Homosteidae see Family Homostiidae Jaekel