Africa’s southern Kalahari Desert is not typically regarded as a hotbed of Stone Age innovations. And yet human culture blossomed there around 105,000 years ago, back when it was green, researchers say.
Calcite crystals and other finds at a South African rock-shelter more than 600 kilometers from the nearest shoreline reflect cultural behaviors on a par with those previously reported for ancient humans living on or near South Africa’s coast, researchers report March 31 in Nature. Those coastal sites date to between roughly 125,000 and 70,000 years ago, including one where locals used tools to make paint out of pigment around 100,000 years ago (SN: 10/13/11).
Given the scarcity of human sites from that time period, it’s hard to know whether cultural innovations emerged independently in groups spread across southern Africa or originated in one particular region before being adopted elsewhere. But the new discoveries fit a scenario in which “the emergence of Homo sapiens involved the interaction of many different populations across Africa,” says archaeologist Jayne Wilkins of Griffith University in Nathan, Australia. “And that included the Kalahari Desert.”
Excavations at Ga-Mohana Hill North Rockshelter, or GHN, uncovered an ancient sediment layer containing 42 burned ostrich eggshell fragments and 22 palm-sized or smaller calcite crystals, Wilkins and her colleagues report.
Like some African hunter-gatherer groups today, ancient people at GHN may have cut holes out of ostrich eggshells to create water containers, the researchers say. Geologic studies indicated that enough rain once fell over the southern Kalahari Desert to have produced year-round water sources for ancient GHN people.
Many eggshell pieces showed discoloration from burning. It’s not clear how that burning occurred. Eggshells lay among numerous animal bones, some of which displayed possible butchery marks and signs of burning.