Ciurcopterus is a genus of eurypterid, an extinct group of aquatic arthropods. Fossils of Ciurcopterus have been discovered in deposits of Late Silurian...

in its genus and was thus named as the type species of a new genus, Ciurcopterus. Studies of specimens referred to this genus resolved long-standing contentiousness...

Ciurcopterus ventricosus (70 cm, 2.3 ft)...

Another species, P. ventricosus, was classified as the separate genus Ciurcopterus in 2007 by O. Erik Tetlie and Derek E. G. Briggs, distinguished primarily...

walking appendages, that along with the characteristics that Slimonia and Ciurcopterus share, suggest that the hughmilleriids are more distant from the pterygotids...

Ciurcopterus ventricosus (70 cm)...

convergent. The discovery of Ciurcopterus, the most primitive known pterygotid, and studies revealing that Ciurcopterus combines features of Slimonia...

walking appendages, that along with the characteristics that Slimonia and Ciurcopterus share, suggest that the hughmilleriids were more distant from the pterygotids...

morphology of its bilobed telson, which is different from the telson of Ciurcopterus, with a dorsal median carinae, and that of Pterygotus, Jaekelopterus...

is the most basal. This debate was resolved with the description of Ciurcopterus, a primitive pterygotid that clearly combines features of Slimonia (especially...