Chelicerata Heymons, 1901
   Scorpiones Koch, 1837 - scorpions
     Orthosternina Pocock, 1911 see Infraorder Orthosterni Pocock, 1911
       1 Genus †Corniops Jeram, 1994, incertae sedis
       2 Superfamily Scorpionioidea Dunlop, Penney & Jekel, 2010, orth. inval. see Superfamily Scorpionoidea Latreille, 1802
       3 Superfamily Buthoidea Koch, 1837
       4 Superfamily Chactoidea Pocock, 1893