†order Eurypterida Burmeister 1843 (eurypterid)
Synonyms: Cyrtoctenida Stoermer and Waterston 1968, Gigantostraca Haeckel 1896
Parent taxon: Sclerophorata according to J. C. Lamsdell 2013
See also Bergström 1968, Dunlop et al. 2020, Sepkoski 2002 and Størmer 1955
Sister taxon: Arachnida
Subtaxa: Belinuropsis Belinuropsis wigudensis Dorfopterus Eurypteracea Eurypterella Eurypterella ornata Eurypterina Holmipterus Marsupipterus Parahughmillera Stylonuracea Stylonurina Unionopterus