QUEENSLAND, AUSTRALIA—Archaeologist Corey O’Driscoll has developed a method of determining if wounds on bones were made by spears thrown from a distance. Indirect evidence from examining stone point, suggests that humans living in Africa began hurling weapons as early as 500,000 years ago, but this evidence is often disputed. To solve this problem, O’Driscoll and a colleague knapped flint spear and arrow points modeled after Middle Stone Age technology from Africa. They then threw the replica spears and fired the replica arrows at lamb and cow carcasses, defleshed the bones, and compared the marks on the bones with a reference collection of butchered animal bones. O’Driscoll found that the butchering marks and the projectile impact marks have clear differences when viewed with a microscope, including traces of stone left in the projectile point wounds. He and Jessica Thompson of the University of Queensland then examined three animal bones from Pinnacle Point Cave in South Africa. Using the new diagnostic criteria, they identified projectile impact marks on all three bones, two of which are between 91,000 and 98,000 years old—the oldest direct evidence for the use of projectile weapons.