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 †Pteraspidiformes Berg, 1940
Family †Psammosteidae Traquair, 1896
Genus †Pycnosteus Preobrazenskii, 1911