Chelicerata Heymons, 1901
   Pseudoscorpiones De Geer, 1778
     Homosyphronida Dunlop, Penney & Jekel, 2020, orth. inval. see Group Homosphyronida Chamberlin, 1929
       1 Atoposyphronida Dunlop, Penney & Jekel, 2020, orth. inval. see Suborder Atoposphyronida Harvey, 2019
       2 Iochierata Dunlop, Penney & Jekel, 2010, orth. inval. see Suborder Iocheirata Harvey, 1992