Poison on the Wind

The Arrowheads That Kept a Secret

At Umhlatuzana Rock Shelter in KwaZulu-Natal, archaeologists have been excavating a long and carefully layered record of human life. Among the finds are small quartz microliths, stone flakes shaped to be hafted onto arrows.

Five quartz-backed microliths from the Umhlatuzana Rock Shelter. They were found with traces of buphandrine and epibuphanisine alkaloid toxins. The inset shows all 10 archaeological artifacts analyzed.Credit...Isaksson et al., Science Advances, 2026

For decades, researchers suspected these tools were used with poison. The shapes fit. The wear patterns fit. What was missing was proof.

Both sides of one of the arrowheads analyzed. The left-hand image shows the organic remains in which the arrowhead residues were identified. Credit: Marlize Lombard

That proof has now arrived. In a study published in Science Advances,¹ Sven Isaksson, Anders Högberg, and Marlize Lombard report chemical traces of toxic plant compounds still clinging to 60,000-year-old arrowheads.

“This is the oldest direct evidence that humans used arrow poison,” said Lombard. “It shows that our ancestors not only invented the bow and arrow much earlier than previously thought, but also understood how to use nature’s chemistry to increase hunting efficiency.”