Protosphyraena was a medium-size predatory fish from the Late Cretaceous period with a long, sword-like snout and blade-like teeth used to stab fleeing prey. It also had long, boney pectoral fins with leading edges serrated like saw blades. The exact purpose of these saw-like fins is a matter of scientific debate. Protosphyraena averaged between six and nine feet (two and three meters) long. It went extinct 65 million years ago.