Chelicerata Heymons, 1901
   Scorpiones Koch, 1837 - scorpions
     †Lobosternina Pocock, 1911
       Superfamily †Isobuthoidea Petrunkevitch, 1913
         1 Family †Eobuthidae Kjellesvig-Waering, 1986 [monotypic]
         2 Family †Eoscorpiidae Scudder, 1884
         3 Family †Isobuthidae Petrunkevitch, 1913
         4 Family †Kronoscorpionidae Kjellesvig-Waering, 1986 [monotypic]
         5 Family †Pareobuthidae Kjellesvig-Waering, 1986 [monotypic]