[Phylum] Chordata Bateson, 1885 - chordates Subphylum Craniata auct. Infraphylum Vertebrata Lamarck, 1801 - vertebrates Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates Class Chondrichthyes Huxley, 1880 - cartilaginous fishes Subclass Euselachii Hay, 1902 - sharks, rays, and related fossils Infraclass Elasmobranchii Bonaparte, 1838 Superorder Squalomorphi Order †Protospinaciformes [monotypic] 1 Family †Protospinacidae Woodward, 1919