[Phylum] [Arthropoda] Siebold, 1848 - arthropods Chelicerata Heymons, 1901 Euchelicerata Weygoldt & Paulus, 1979 [Order] †Eurypterida Burmeister, 1843 - eurypterids Genus †Unionopterus Chernyshev, 1948, incertae sedis