Chelicerata Heymons, 1901
Pseudoscorpiones De Geer, 1778
1 †Palaeosphyronida Harvey, 2019 [monotypic]
2 Heterosyphronida Dunlop, Penney & Jekel, 2020, orth. inval.
see Suborder Heterosphyronida Chamberlin, 1929
3 Homosyphronida Dunlop, Penney & Jekel, 2020, orth. inval.
see Group Homosphyronida Chamberlin, 1929