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.
Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.