Chelicerata Heymons, 1901 Scorpiones Koch, 1837 - scorpions †Holosternina Kjellesvig-Waering, 1986 Superfamily †Mesophonoidea Wills, 1910 Family †Heloscorpionidae Kjellesvig-Waering, 1986 [monotypic] 1 Genus †Heloscorpio Kjellesvig-Waering, 1986