[Phylum] Chordata Bateson, 1885 - chordates
   Subphylum Craniata auct.
     Infraphylum Vertebrata Lamarck, 1801 - vertebrates
       Superclass †Anaspidomorphi
         Class †Anaspida Traquair
           Order †Anaspidiformes
             Family †Birkeniidae Traquair, 1900
               1 Genus †Birkenia Traquair, 1899