Class †Placodermi McCoy, 1848 Order †Arthrodira Woodward, 1891 see [unranked] Arthrodira Woodward, 1891 †Aspinothoracida see [unranked] Aspinothoracidi Stensiö, 1959 Family †Selenosteidae Dean, 1901 Genus †Melanosteus Lelièvre & Goujet, 1987 1 †Melanosteus occitanus