Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct. see Subphylum Vertebrata Cuvier, 1812
       Vertebrata (Lamarck, 1801) - vertebrates see Subphylum Vertebrata Cuvier, 1812
         Superclass †Pteraspidomorphi Goodrich, 1909 [monotypic]
           Class †Pteraspidomorphi Goodrich, 1909
             Subclass †Heterostraci Lankester, 1868
               Order †Cyathaspidiformes (Kaier, 1930)
                 Family †Cyathaspididae Flower & Wayland-Smith, 1952
                   1 Genus †Anglaspis Jaekel, 1927
                   2 Genus †Dinaspidella Strand, 1934
                   3 Genus †Irregulareaspis Zych, 1931
                   4 Genus †Poraspis Kiaer, 1930
                   5 Genus †Torpedaspis Broad & Dineley, 1973