Phylum [Vertebrata] Lamarck, 1801 see Infraphylum Vertebrata Lamarck, 1801 Class Agnatha Cope, 1889 1 Subclass †Pteraspidomorphi Goodrich, 1909 see Class Pteraspidomorphi Goodrich, 1909 2 Subclass †Cephalaspidomorphi Kiaer & Stensiö, 1920 see Class Agnatha Cope, 1889