[Phylum] [Arthropoda] Siebold, 1848 - arthropods
   Chelicerata Heymons, 1901
     Euchelicerata Weygoldt & Paulus, 1979
       Xiphosura Latreille, 1802 - horseshoe crabs see Class Xiphosura Latreille, 1802
         Prosomapoda Lamsdell, 2013
           [Class] Xiphosura Latreille, 1802 [monotypic] - horseshoe crabs
             [Order] Xiphosurida Latreille, 1802
               [Suborder] Limulina Richter & Richter, 1929
                 Superfamily Limuloidea Leach, 1819
                   1 Genus †Valloisella Racheboeuf, 1992
                   2 Family †Austrolimulidae Riek, 1955
                   3 Family Limulidae Leach, 1819