Stone tools unearthed in Saudi Arabia’s inhospitable Nefud Desert indicate that members of our genus Homo had ventured beyond the familiar borders of Africa and the Levant sometime between 300,000 and 500,000 years ago. And according to climate data captured in the bones of animals found at the site, the environment they moved into may not have been that different from the one they left behind in East Africa. That may help anthropologists better understand the role of environment—and the ability to adapt to challenging new landscapes—in shaping human evolution and global expansion.
The things they left behind
Archaeologist Patrick Roberts of the Max Planck Institute for the Science of Human History and his colleagues recently discovered a handful of stone tools in a sandy layer of soil beneath the dry traces of a shallow Pleistocene lake at Ti’s al Ghadah, in the Nefud Desert of northern Saudi Arabia. The soil layer dated to between 300,000 and 500,000 years ago, and it also contained fossilized remains of grazing animals, water birds, and predators like hyena and jaguar. Many of the bones seem to bear the marks of butchering by tool-wielding hominins.
Archaeologists had found other fossils at the site with possible cut marks, but, without stone tools, it’s difficult to determine if a notch in a fossil rib was put there by a human hand and not another predator or natural process. The tools—six sharp brown chert flakes and a scraper—make a much clearer case. Roberts and his colleagues say they’re the oldest radiometrically dated hominin artifacts in the Arabian Peninsula, edging out the previous contender by 100,000 years.