Kingdom Animalia Linnaeus, 1758 - animals Phylum Arthropoda Siebold, 1848 - arthropods Superclass Chelicerata Heymons, 1901 see Subphylum Chelicerata Heymons, 1901 1 Class Merostomata Dana, 1852 - horseshoe crabs see Class Xiphosura Latreille, 1802 2 Class Arachnida Lamarck, 1801