Phylum [Vertebrata] (Lamarck, 1801) Class Agnatha Cope, 1889 Subclass †Pteraspidomorphi Goodrich, 1909 see Class Pteraspidomorphi Goodrich, 1909 Order †Thelodontida see Order Thelodonti Jaekel, 1911 Genus †Thelodus Agassiz, 1839