Acutiramus is an extinct genus of eurypterid which lived in the Late Silurian (Ludlow) to Early Devonian. Acutiramus was among the largest eurypterids, estimated to be about 2 meters long, and pincers about 5 centimeters long. It was eclipsed in size by its relatives Pterygotus and Jaekelopterus. Many authorities regard Acutiramus as a synonym of Pterygotus.