Dolichopterus is a genus of prehistoric sea scorpions, arthropods in the order Eurypterida.

Fossils of Dolichopterus have been discovered in deposits ranging from Silurian to Devonian, and have been referred to several different species, some of them of dubious affinity to this genus.

Dolichopteridae, which lived in the Silurian and Devonian periods, had outer surfaces that were either smooth with pustules and semilunar scales.

Their chelicerae were small, and the first three pairs of walking lags were stout, with powerful spines.

[2] Dolichopterus is distinguishable by its nearly smooth outer surface; its subquadrate prosoma (head), and the slightly serrated margins on the distal joints and lobes of the swimming legs.