Chelicerata Heymons, 1901
   Scorpiones Koch, 1837 - scorpions
     †Holosternina Kjellesvig-Waering, 1986
       Superfamily †Gigantoscorpionoidea Kjellesvig-Waering, 1986 [monotypic]
         Family †Gigantoscorpionidae Kjellesvig-Waering, 1986
           1 Genus †Gigantoscorpio Størmer, 1963
           2 Genus †Petaloscorpio Kjellesvig-Waering, 1986