Vertebrata Cuvier, 1812 - vertebrates
   Gnathostomata
     Class †Placodermi McCoy, 1848
       Order †Arthrodira Woodward, 1891 see Order Arthrodiriformes Grande & Eastman, 1986
         Suborder †Brachythoraci Gross, 1932
           Superfamily †Dinichthyloidea
             1 Family †Dinichthyidae Newberry, 1885
             2 Family †Leiosteidae Stensiö, 1963
             3 Family †Trematosteidae Gross, 1932