Chelicerata Heymons, 1901
Pseudoscorpiones De Geer, 1778
Heterosyphronida Dunlop, Penney & Jekel, 2020, orth. inval.
see Suborder Heterosphyronida Chamberlin, 1929
Superfamily Chthonoidea Dunlop, Penney & Jekel, 2010, orth. inval.
see Superfamily Chthonioidea Daday, 1888
Family Lechytidae orth. inval.
see Family Lechytiidae Chamberlin, 1929