Ancient human artefacts found near caves in Arabian desert

The dry deserts of north-eastern Saudi Arabia were once wet enough to host vibrant communities of animals – and researchers have just found evidence that ancient hominins lived there too.

“This paper provides the first outline of the archaeological record of inland north-east Arabia – a vast region that has been unstudied,” says Monika Markowska at Northumbria University, UK, who wasn’t involved in the work.

The research focuses on a mostly underexplored region of the Arabian peninsula between Qatar and Kuwait. Records of a prehistoric human presence in this area are non-existent, yet scientists know it once received enough rain to support a thriving ecosystem.

“Hominins have been in Arabia for at least the last 500,000 years – probably in multiple waves of occupation,” says Huw Groucutt at the University of Malta.

To better understand the area’s potential ancient hominin inhabitants, Groucutt and his colleagues identified ancient rivers and caves located near deposits of chert, a hard and dense rock that prehistoric humans used to make tools. “Caves are often important locations for archaeological, fossil and climatic records,” says Groucutt.

In total, they searched 79 caves and their surroundings. Several of them contained evidence for the presence of ancient humans and animals. One cave was adjacent to a site with more than 400 stone tools scattered across its floor. Inside the caves, they also discovered the remains of ancient reptiles, bats, birds, camels, gazelles, hyenas and wolves.

By analysing the style of the stone tools, Groucutt and his colleagues determined that the hominins lived by the caves between 10,000 and 100,000 years ago.

“Although today [Arabia] acts as a barrier for species movement, past climate-driven windows of opportunity may have created more favourable conditions for occupation and migration,” says Markowska. “The exceptional preservation of thousands of bones in these caves provides rare insights into past ecosystems.”

Team member Michael Petraglia at Griffith University, Australia, has been researching the archaeology of Arabia for many years. “This paper is one more step towards understanding the caves and rivers, what they contain and what they tell us about life in the dynamic ecosystems of Arabia,” he says.