Kingdom Animalia Linnaeus, 1758 - animals Phylum Mollusca Linnaeus, 1758 - molluscs Subphylum Cyrtosoma Runnegar & Pojeta Jr., 1974 see Phylum Mollusca Linnaeus, 1758 Class Cephalopoda Cuvier, 1795 - cephalopods Subclass Nautiloidea Agassiz, 1848 Genus †Discosorus Hall, 1851[1852]