Chelicerata Heymons, 1901
   Xiphosura s. lat. Latreille, 1802 - horseshoe crabs see Class Xiphosura Latreille, 1802
     Prosomapoda Lamsdell, 2013
       Planaterga Lamsdell, 2013
         1 Genus †Bembicosoma Laurie, 1899
         2 Genus †Cyamocephalus Currie, 1927
         3 Genus †Pseudoniscus Nieszkowski, 1859
         4 Genus †Bunaia Clarke, 1920
         5 Family †Bunodidae Packard, 1886