Arthropoda Siebold, 1848 - arthropods
   Euarthropoda
     Subphylum Chelicerata Heymons, 1901
       Euchelicerata Weygoldt & Paulus, 1979
         Prosomapoda Lamsdell, 2013
           Xiphosura Latreille, 1802 - horseshoe crabs
             1 Genus †Kasibelinurus Pickett, 1993
             2.1 Order Xiphosurida Latreille, 1802
             2.2 Genus †Willwerathia Størmer, 1969
             3 ?Genus †Maldybulakia Tesakov & Alekseev, 1998