Chelicerata Heymons, 1901 †Eurypterida Burmeister, 1843 - eurypterids †Stylonurina Diener, 1924 Superfamily †Kokomopteroidea Kjellesvig-Waering, 1966 Family †Hardieopteridae Tollerton, 1989 1 Genus †Hallipterus Kjellesvig-Waering, 1963 2 Genus †Hardieopterus Waterson, 1979 3 Genus †Tarsopterella Størmer, 1951