Chordata Bateson, 1885 - chordates Class †Ostracophori Order †Osteostraci Lankester, 1868 - osteostracans see Order Cephalaspidiformes Halstead Tarlo, 1967 Family †Cephalaspidae Agassiz, 1844 see Family Cephalaspididae Agassiz, 1844, nom. praeval.