7000-Yr-Old Bone Arrows Tipped With Poison Stuns Researchers, Possibly World's Oldest Poisoned Arrow

Researchers have possibly found a seven-millenium-old arrow poison from bone arrowheads excavated in 1983. The arrowheads were nestled in the femur bone of an antelope estimated to be 7,000 years old, uncovered from Kruger Cave cave in South Africa, stated Science Alert. Along with the femur, several other artifacts were unearthed from the cave which were kept at the University of the Witwatersrand's Archaeology Department storerooms. Archaeological investigations in the cave during 2022, caused researchers to re-examine the bone which led to the finding of arrowheads. Findings regarding the poison have been published in Science.

Experts investigated the matrix surrounding the arrowheads through Micro-CT. The results clearly showed that the matrix inside the marrow cavity was not typical sediment. Later it was detected to be a multi-component poison. As per an examination, there were two toxic plant ingredients in this poison, and possibly a third one. Chemical analysis revealed the presence of two toxic cardiac glycosides—digitoxin and strophanthidin. These materials primarily disrupt the functioning of the heart. These two glycosides have been detected by experts in certain poisons associated with bow hunting. There were also traces of ricinoleic acid in the poison. Ricinoleic acid is a possible byproduct that comes due to the oxidation of toxic lectin ricin

According to researchers, all these compounds do not occur in the same plant. This indicates that multiple plants were involved in the making of this poison. None of the plants that grow around Kruger Cave contain digitoxin and strophanthin. Neither did these compounds get spotted in the excavated materials of the cave. This means that either people were traveling long distances to make this poison, or it was an output of established trade taking place in floral communities. Evidence of sea shell trade during this period has been observed by researchers, but this is the first time proof of similar movement in the case of non-domesticated plants has been noted by experts. The fact that people in those times knew what ingredient to take to make a poison, showcases that traditional pharmacological knowledge systems were present even seven millenniums ago. 

According to historical records, this practice of using poison in hunting is older and came into being in Africa 60,000 to 70,000 years ago alongside projectile technology. However, evidence of poison from that period has been scarce. Therefore, chemical verification of this practice at that time has not been done by experts.  The mixture found in Kruger Cave is the oldest confirmed use of two or more plat toxins as poison on arrowheads. The finding is valuable for experts as it is proof of the superior cognitive qualities and traditional pharmacological knowledge practiced by people of those times.

This is the oldest example of a mixed poison that has been noted by researchers. In the past, archaeologists have located older instances of single-component poison, stated Archaeology Magazine. One of them was observed on a 24,000-year-old spatula inside Border Cave, which was found to contain residues of ricinoleic acid.