Arthropoda Siebold, 1848 - arthropods
   Euarthropoda
     Subphylum Chelicerata Heymons, 1901
       Euchelicerata Weygoldt & Paulus, 1979
         Prosomapoda Lamsdell, 2013
           Xiphosura Latreille, 1802 - horseshoe crabs
             Order Xiphosurida Latreille, 1802
               Limulina Richter & Richter, 1929