Class †Placodermi McCoy, 1848
   Order †Arthrodira Woodward, 1891 see [unranked] Arthrodira Woodward, 1891
     †Aspinothoracida see [unranked] Aspinothoracidi Stensiö, 1959
       Family †Selenosteidae Dean, 1901
         1 Genus †Gymnotrachelus Dunkle & Bungart, 1939, sedis mutabilis
         2 Genus †Pachyosteus Jaekel, 1903, sedis mutabilis
         3 Genus †Stenosteus Dean, 1901, sedis mutabilis
         4.1.1 Genus †Selenosteus Dean, 1901
         4.1.2.1 Genus †Walterosteus Stensiö, 1959
         4.1.2.2.1 Genus †Enseosteus Jaekel, 1919
         4.1.2.2.2 Genus †Draconichthys Rücklin, 2011
         4.2.1 Genus †Rhinosteus Jaekel, 1911
         4.2.2.1 Genus †Melanosteus Lelièvre & Goujet, 1987
         4.2.2.2.1 Genus †Driscollaspis Rücklin, Long & Trinajstic, 2015
         4.2.2.2.2 Genus †Brachyosteus Jaekel, 1927