TECHNOLOGY × SUBSISTENCE

Katanda, the Oldest Bone Harpoons

~90,000 years ago

Palaeolithic · Middle Stone Age · Last glacial

Katanda is a group of three archaeological sites on the Upper Semliki River, in the Western Rift Valley of what is now the Democratic Republic of the Congo. Their Middle Stone Age levels yielded points carved from bone, some barbed and some not, together with a daggerlike object and abundant fish remains dominated by catfish. Working bone into such shapes, and fishing on that scale, were held to belong to a much later period. Several independent clocks were therefore applied to the deposits: electron spin resonance, thermoluminescence, optically stimulated luminescence, uranium series and amino acid racemisation all returned ages older than 89,000 years, and the fauna and the stratigraphy agree with that figure. A later reworking of the luminescence measurements, on additional samples, supported the original result.

Why it matters

Worked bone carried a heavy argument at the time of the discovery. Formal bone tools became a regular feature of European sites only after about 40,000 years ago, where they served as a marker of the arrival of anatomically modern humans, and they remained rare in African deposits before about 25,000 years ago. That scarcity was read as evidence that the capacities behind such objects were recent. Katanda places the same manufacturing skill, and a subsistence specialised on large river fish, some fifty thousand years earlier and on another continent.

Dating & uncertainty

The published age is older than 89,000 years, with an asymmetric uncertainty of plus 22,000 and minus 15,000 years, which places the deposits between roughly 74,000 and 111,000 years. Five independent methods were applied, and the fauna and the stratigraphy agree with the outcome. The luminescence measurements were nonetheless reworked a few years later, the first readings having suffered from a defect known as radiation quenching: additional samples, heated more strongly before measurement to remove it, gave scattered but concordant ages and supported the first estimate.

Sources

1. Yellen et al. (1995), Science · A Middle Stone Age Worked Bone Industry from Katanda, Upper Semliki Valley, Zairedoi:10.1126/science.7725100
2. Brooks et al. (1995), Science · Dating and Context of Three Middle Stone Age Sites with Bone Points in the Upper Semliki Valley, Zairedoi:10.1126/science.7725099
3. Feathers et al. (2001), Quaternary Science Reviews · Luminescence dating at Katanda: a reassessmentdoi:10.1016/s0277-3791(00)00041-x
4. Henshilwood et al. (2001), Journal of Human Evolution · An early bone tool industry from the Middle Stone Age at Blombos Cave, South Africa: implications for the origins of modern human behaviour, symbolism and languagedoi:10.1006/jhev.2001.0515

Our species’ history as one day

17:08:346 h 51 min before midnight

if the 315,000 years of Homo sapiens were compressed into a single day