Chelicerata Heymons, 1901
Status: extant; Count: 2c;12o; †6o;2f;23g
   Scorpiones Koch, 1837 - scorpions
  Status: extant; Count: [g†g] 15f;5g; †43f;92g [27 Dec 2020]
     Orthosternina Pocock, 1911 see Infraorder Orthosterni Pocock, 1911
    Status: extant; Count: [g†g] 15f;5g; †8f;30g [27 Dec 2020]
       Superfamily Scorpionioidea Dunlop, Penney & Jekel, 2010, orth. inval. see Superfamily Scorpionoidea Latreille, 1802
      Status: extant; Count: [g†g] 1f; †1f;3g
         Family †Palaeopisthacanthidae Kjellesvig-Waering, 1986
        Status: fossil; Count: [†g] †2g [27 Dec 2020]
           Genus †Cryptoscorpius Jeram, 1994
          Status: fossil; Count: -