[Phylum] Chordata Bateson, 1885 - chordates Subphylum Craniata auct. Infraphylum Vertebrata Lamarck, 1801 - vertebrates Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates Class †Placodermi McCoy, 1848 †Arthrodira Woodward, 1891 Order †Phlyctaeniiformes Suborder †Phlyctaenioidei Family †Arctaspididae Goujet, 1984 1 Genus †Arctaspis Heintz, 1929