In a remarkable breakthrough that reshapes our understanding of early human behavior and cognition, scientists have uncovered the oldest direct evidence of poisoned weapons in the world. Traces of plant-based poison have been detected on 60,000-year-old arrowheads unearthed in South Africa, revealing that Stone Age hunter-gatherers not only invented projectile technology far earlier than previously documented, but also possessed a sophisticated knowledge of toxic plants and hunting strategies.
A Groundbreaking Archaeological Discovery
The discovery comes from the Umhlatuzana Rock Shelter in KwaZulu-Natal, South Africa, where archaeologists have been excavating remains of prehistoric human activity for decades. Among thousands of stone artifacts, researchers selected a set of tiny quartz arrowheads — dating to roughly 60,000 years ago during the late Middle Stone Age — for chemical analysis. These backed microliths are consistent with parts of arrow tips used by hunter-gatherers in the region.
Using gas chromatography-mass spectrometry, a laboratory technique for separating and identifying chemical substances, scientists identified two toxic alkaloids — buphandrine and epibuphanisine — on several of the arrowheads. These chemicals are characteristic compounds found in the bulb of a poisonous plant known locally as gifbol (Boophone disticha), which historically has been used by traditional hunters to tip arrows and other weapons.
These findings are published in the peer-reviewed journal Science Advances, and represent the earliest direct chemical evidence that humans intentionally applied poison to hunting tools. Prior to this discovery, the oldest confirmed poison use on arrows dated back only about 7,000 years, uncovered at Kruger Cave in South Africa, and was thought to be a later technological innovation.
What the Poisoned Arrows Reveal
The chemical residues were found on five out of ten quartz microliths analyzed, indicating that these arrow fragments had been treated with toxic substances before being used. The fact that these poisons are plant-derived and not naturally occurring on the stone tools supports the interpretation that ancient people intentionally used them as part of their hunting strategy.
Moreover, similar poisonous compounds were found on a set of 18th-century arrowheads from South Africa’s historical collections, suggesting a long continuity of indigenous knowledge about poisonous plants over millennia. This continuity of tradition provides a unique bridge between prehistoric and more recent hunting practices.
Evidence of Complex Human Behavior
The discovery of poison on Stone Age arrowheads has profound implications for our understanding of early human intelligence and cultural complexity. Crafting poisoned weapons would have required several steps: identifying the right plant species, extracting and processing toxic compounds, mixing the poison with adhesives or binding materials to attach it to the arrow tips, and finally incorporating these enhanced weapons into hunting strategies that exploited their delayed effects.
Unlike a spear or a club that relies on physical force, a poisoned arrow depended on chemical effects to weaken prey over time. Once struck, an animal might flee and later succumb to the poison, meaning that prehistoric hunters had to anticipate delayed outcomes, track wounded animals, and adjust their hunting tactics accordingly. This suggests a high degree of planning, cause-and-effect reasoning, and cognitive sophistication.
Experts say this behavior aligns with what anthropologists consider modern human cognition — the ability to use abstract thinking, knowledge of natural materials, and foresight in complex problem-solving. Using poison indicates that our ancestors had procedural knowledge and could exploit the biochemistry of plants in deliberate ways.
The Role of Gifbol (Boophone disticha)
The plant identified as the source of the poison, Boophone disticha, is a bulbous species native to southern Africa. Known colloquially as the “poison bulb,” it contains potent alkaloids that can disrupt nerve and heart function. Traditional hunting communities in the region have long recognized its toxic properties and used it for arrow poisons, suggesting a deep cultural understanding of plant toxicity.
While it is unclear whether Boophone disticha grew exactly at the Umhlatuzana site 60,000 years ago, the plant’s regional presence within approximately 12.5 kilometers (8 miles) today makes it the most likely source. The preservation of chemical residues over such a vast timescale is extraordinary and speaks to both the stability of these compounds under particular conditions and the careful work of the research team.
Rewriting the Timeline of Hunting Technology
Before this find, the earliest direct evidence of poisoned weapons dated back only a few thousand years. By pushing poison use back to 60,000 years ago, the study challenges assumptions about when complex technologies and cognitive skills — such as understanding toxicology and planning delayed effects — emerged in human history.
This discovery also suggests that the bow and arrow itself was part of early modern human behavior in southern Africa. While the exact age of bow use remains debated, evidence from other sites shows that early humans developed projectile technology tens of thousands of years ago, and the addition of poison boosts our appreciation for the sophistication of early hunting systems.
Broader Implications for Anthropology
The implications of finding poisoned arrows in the Late Pleistocene extend beyond hunting practices. It suggests that early humans had a deep ecological knowledge — an understanding of their natural environment, the effects of specific plants, and how to use that knowledge for survival. This aligns with other behavioral innovations of the period, such as symbolic art, personal ornamentation, and advanced tool manufacturing.
Additionally, it opens up new avenues for archaeological research. The researchers hope to analyze more layers at the Umhlatuzana Rock Shelter and other sites to determine whether poison use was a continuous tradition or developed intermittently. More chemical analyses of prehistoric tools may reveal how widespread this practice was across time and geography.