†Placodermi McCoy, 1848 †Arthrodira Woodward, 1891 †Brachythoraci Gross, 1932 †Eubrachythoraci Miles, 1971 †Coccosteomorphi Stensiö, 1944 Genus †Harrytoombsia Miles & Dennis, 1979 1 †Harrytoombsia elegans Miles & Dennis, 1979