[Phylum] Chordata Bateson, 1885 - chordates
   Subphylum Craniata auct.
     Infraphylum Vertebrata Lamarck, 1801 - vertebrates
       Superclass †Pteraspidomorphi Goodrich, 1909 [monotypic]
         Class †Pteraspidomorpha
           Subclass †Heterostraci Lankester, 1868
             Order †Cyathaspidiformes Kiaer, 1930
               Suborder †Amphiaspidoidei
                 1 Family †Amphiaspididae Obruchev, 1939
                 2 Family †Gabreyaspididae Novitskaya, 1968 see Family Amphiaspididae Obruchev, 1939
                 3 Family †Olbiaspididae Obruchev, 1964 see Family Amphiaspididae Obruchev, 1939
                 4 Family †Edaphaspididae Novitskaya, 1968 see Family Amphiaspididae Obruchev, 1939