Phylum [Vertebrata] (Lamarck, 1801) Class Chondrichthyes Huxley, 1880 - cartilaginous fishes Subclass Holocephali Bonaparte, 1832 Order Chimaerida see Order Chimaeriformes Obruchev, 1953 1 Genus †Deltoptychius Morris & Roberts, 1862 2 Genus †Ischyodus Egerton, 1843