[Phylum] Chordata Bateson, 1885 - chordates Subphylum Craniata auct. Infraphylum Vertebrata Lamarck, 1801 - vertebrates Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates Class †Placodermi McCoy, 1848 Order †Ptyctodontiformes [monotypic] Family †Ptyctodontidae Woodward, 1891 Genus †Ptyctodus Pander, 1858, nom. protect.