[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 †Siberiaspidoidei [monotypic]
                 Family †Siberiaspididae Novitskaya, 1968 see Family Amphiaspididae Obruchev, 1939
                   1 Genus †Siberiaspis Obruchev, 1964
                   2 Genus †Tuxeraspis Novitskaya, 1971