JOHANNESBURG, South Africa, Aug. 26 (UPI) -- Anthropologists in South Africa say they've discovered 64,000-year-old stone points that are the earliest direct evidence of human-crafted arrows.
Remnants of blood and bones found on the stone points provide clues that they were the tips of hunting arrows, the BBC reported Thursday.
Scientists from the University of Johannesburg excavated the arrowheads from layers of ancient sediment in Sibudu Cave in South Africa.
Marlize Lombard described her study of the artifacts as "stone age forensics."
"We took the [points] directly from the site, in little [plastic] baggies, to the lab," she said.
Examining where they had been impacted and damaged showed that they were very likely the tips of projectiles rather than sharp points on the end of hand-held spears, Lombard said.
They contained traces of glue, a plant-based resin scientists think was used to fasten them to a wooden shaft.
"The presence of glue implies that people were able to produce composite tools -- tools where different elements produced from different materials are glued together to make a single artifact," Lombard said.