Phylum [Vertebrata] (Lamarck, 1801) Class Agnatha Cope, 1889 Subclass †Cephalaspidomorphi Moy-Thomas & Mile, 1971 see Class Agnatha Cope, 1889 Order †Osteostraci - osteostracans see Order Cephalaspidiformes Genus †Tremataspis Schmidt, 1866