Phylum [Vertebrata] Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801 Class Agnatha Cope, 1889 Subclass †Pteraspidomorphi Goodrich, 1909 see Class Pteraspidomorphi Goodrich, 1909 Order †Heterostraci Lankester, 1868 - heterostracans see Subclass Heterostraci Lankester, 1868 Family †Pteraspidae see Family Pteraspididae Claypole, 1885 Genus †Pteraspis Kner, 1847