Vertebrata Cuvier, 1812 - vertebrates see Infraphylum Vertebrata Lamarck, 1801 Class Agnatha Cope, 1889 [paraphyletic] Subclass Cephalaspidomorpha see Class Agnatha Cope, 1889 Order †Osteostraci Lankester, 1868 - osteostracans see Order Cephalaspidiformes Halstead Tarlo, 1967 Family †Sclerodontidae Berg, 1940 see Family Tremataspididae Woodward, 1891, nom. praeval.