vertebrates Lamarck, 1801 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
   †Pteraspidimorphi [paraphyletic]
     †Heterostraci Lankester, 1868, sedis mutabilis - heterostracans
       Family †Cyathaspididae Kiaer, 1932, nom. praeval. [paraphyletic]
         Order †Pteraspidiformes Berg, 1940
           1 Genus †Xylaspis Pernegre, 2004
           2.1.1.1 Genus †Woodfjordaspis Pernegre, 2006
           2.1.1.2 Genus †Doryaspis White, 1935
           2.1.2 [Suborder] †Psammosteida Kiaer, 1932 see Suborder Psammosteoidei Kiaer, 1932
           2.2.1 Genus †Europrotaspis White, 1961
           2.2.2.1 †Zascinaspis heintzi (Brotzen, 1936)
           2.2.2.2.1 Genus †Gigantaspis Heintz, 1962, sedis mutabilis
           2.2.2.2.2 Genus †Escharaspis Elliott, 1983, sedis mutabilis
           2.2.2.2.3.1.1 Genus †Stegobranchiaspis Elliott, 1983
           2.2.2.2.3.1.2 Genus †Protopteraspis Leriche, 1924
           2.2.2.2.3.2.1 †Zascinaspis carmani (Denison, 1960)
           2.2.2.2.3.2.2.1.1.1 Genus †Unarkaspis Elliott, 1983
           2.2.2.2.3.2.2.1.1.2 Genus †Larnovaspis Blieck, 1984
           2.2.2.2.3.2.2.1.2.1 Genus †Brachipteraspis Brotzen, 1936
           2.2.2.2.3.2.2.1.2.2.1 Genus †Errivaspis Blieck, 1984
           2.2.2.2.3.2.2.1.2.2.2.1 Genus †Rhinopteraspis Jaekel, 1919
           2.2.2.2.3.2.2.1.2.2.2.2 Genus †Althaspis Zych, 1931
           2.2.2.2.3.2.2.2.1 Genus †Loricopteraspis Tarlo, 1961
           2.2.2.2.3.2.2.2.2.1 Genus †Pteraspis Kner, 1847
           2.2.2.2.3.2.2.2.2.2.1 Genus †Lampraspis Denison, 1970
           2.2.2.2.3.2.2.2.2.2.2.1 Genus †Mylopteraspidella Blieck, 1984
           2.2.2.2.3.2.2.2.2.2.2.2.1.1.1 Genus †Podolaspis Zych, 1931
           2.2.2.2.3.2.2.2.2.2.2.2.1.1.2 Genus †Dnestraspis Novitskaya, 1983
           2.2.2.2.3.2.2.2.2.2.2.2.1.2.1.1 Genus †Pavloaspis Voichyshyn, 1999
           2.2.2.2.3.2.2.2.2.2.2.2.1.2.1.2 Genus †Parapteraspis Stensiö, 1958
           2.2.2.2.3.2.2.2.2.2.2.2.1.2.2.1 Genus †Miltaspis Blieck, 1981
           2.2.2.2.3.2.2.2.2.2.2.2.1.2.2.2.1 Genus †Mitraspis Elliott, Schultze & Blieck, 2015, nom. illeg.
           2.2.2.2.3.2.2.2.2.2.2.2.1.2.2.2.2 Genus †Canadapteraspis Dineley & Loeffler, 1976
           2.2.2.2.3.2.2.2.2.2.2.2.2.1 Genus †Semipodolaspis Voichyshyn, 2011
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.1 Genus †Djurinaspis Novitskaya, 1983
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.1 Genus †Alaeckaspis Voichychyn, 1999
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.1 Genus †Panamintaspis Elliott & Ilyes, 1996
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.1 Genus †Blieckaspis Elliott & Ilyes, 1996
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.1.1 Genus †Pirumaspis Ilyes & Elliott, 1994
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.1.2 Genus †Lamiaspis Ilyes & Elliott, 1994
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.1 Genus †Protaspis Bryant, 1933, sedis mutabilis
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.2 Genus †Eucyclaspis Denison, 1970, sedis mutabilis
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.3.1 Genus †Tuberculaspis Ilyes & Elliott, 1994
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.3.2.1 Genus †Psephaspis Ørvig, 1961, sedis mutabilis
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.3.2.2 Genus †Helaspis Elliott, Dineley & Johnson, 2000, nom. illeg., sedis mutabilis
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.3.2.3 Genus †Cyrtaspidichthys Whitley, 1940, sedis mutabilis
           2.2.2.2.3.2.2.2.2.2.2.2.2.2.2.2.2.2.2.3.2.4 Genus †Cosmaspis Denison, 1970, sedis mutabilis