[Phylum] Chordata Bateson, 1885 - chordates Subphylum Craniata auct. Infraphylum Vertebrata Lamarck, 1801 - vertebrates Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates Class †Placodermi McCoy, 1848 Order †Pseudopetalichthyiformes [monotypic] Family †Paraplesiobatidae Berg, 1940 Genus †Nessariostoma Broili, 1933