vertebrates Lamarck, 1801 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
   Class †Cephalaspidomorphi Kiaer & Stensiö, 1920 see Class Osteostraci Lankester, 1868
     Subclass †Osteostraci Lankester, 1868 see Class Osteostraci Lankester, 1868
       Order †Cephalaspidiformes Halstead Tarlo, 1967
         Suborder †Cephalaspidoidei Halstead Tarlo, 1967
           1 Family †Cephalaspididae Agassiz, 1844, nom. praeval.
           2 Family †Parameteoraspididae Afanassieva, 1991
           3 Family †Pattenaspididae Stensiö, 1958