Chelicerata Heymons, 1901
   Scorpiones Koch, 1837 - scorpions
     Orthosternina Pocock, 1911 see Infraorder Orthosterni Pocock, 1911
       Superfamily Chactoidea Pocock, 1893
         01 Family †Palaeoeuscorpiidae Lourenço, 2003
         02 Family Chactidae Pocock, 1893
         03 Family Akravidae Levy, 2007
         04 Family Chaerilidae Pocock, 1893
         05 Family Diplocentridae Karsch, 1880
         06 Family Euscorpiidae Laurie, 1896
         07 Family Heteroscorpionidae Kraepelin, 1905
         08 Family Hemiscorpiidae Pocock, 1893
         09 Family Iuridae Thorell, 1876
         10 Family Scorpionidae Latreille, 1802
         11 Family Superstitioniidae Stahnke, 1940
         12 Family Troglotayosicidae Lourenço, 1998
         13 Family Vaejovidae Thorell, 1876