[Phylum] [Arthropoda] Siebold, 1848 - arthropods
   Chelicerata Heymons, 1901
     Euchelicerata Weygoldt & Paulus, 1979
       [Order] †Eurypterida Burmeister, 1843 - eurypterids
         [Suborder] †Eurypterina Burmeister, 1843
           [Infraorder] †Diploperculata Lamsdell, Hoşgör & Selden, 2013
             Superfamily †Pterygotioidea Dunlop, Penney & Jekel, 2010, orth. inval. see Superfamily Pterygotoidea Clarke & Ruedemann, 1912
               Family †Pterygotidae Clarke & Ruedemann, 1912
                 1 Genus †Acutiramus Ruedemann, 1935
                 2 Genus †Ciurcopterus Tetlie & Briggs, 2009
                 3 Genus †Erettopterus Salter, 1859
                 4 Genus †Jaekelopterus Waterston, 1964
                 5 Genus †Necrogammarus Woodward, 1870
                 6 Genus †Pterygotus Agassiz, 1845