Kingdom Animalia Linnaeus, 1758 - animals Phylum Arthropoda Siebold, 1848 - arthropods Subphylum Cheliceriformes Class Pycnogonida Latreille, 1810 - pycnogonids Family Nymphonidae Wilson, 1878 Genus Sexanymphon Hedgpeth & Fry, 1964