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.
Comment: Evidently our climate is always changing and the human story is not as clear as was once thought: