A pair of 77,000-year-old pieces of engraved ochre found in a South African cave lend credence to the view that symbolic forms of thinking, considered crucial for modern human behavior, emerged surprisingly early in the Stone Age.
An international research team led by Christopher S. Henshilwood of the South African Museum in Cape Town unearthed the artifacts in the Blombos Cave near the country's southern tip. Both chunks of ochre have surfaces that were ground smooth before cross-hatched designs were etched into them, the researchers report in a forthcoming issue of Science.
The scientists determined the engraved objects' age by analyzing radioactive isotopes in charred bits of stone from the layer of soil in which the artifacts were unearthed.
Christopher S. Henshilwood
Iziko Museums of Cape Town
South African Museum
Post Office Box 61
Cape Town 8000
Henshilwood, C.S., et al. 2001. 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 language. Journal of Human Evolution 31(Dec. 1):631-678.