Stone Age hunters repeatedly lived in a rock shelter nearly 3,500 meters up Ethiopia's Bale Mountains between 47,000 and 31,000 years ago, an international team reported in the journal Science in August 2019.
The Sanetti Plateau in Ethiopia's Bale Mountains, photographed on December 23, 2017. (Charles J. Sharp / Wikimedia Commons, CC BY-SA 4.0) [file photo]
The site, the Fincha Habera rock shelter, sits 3,469 meters above sea level. Archaeologists found hundreds of stone tools, thousands of discarded animal bones and ancient hearths in its sediment, Ars Technica reported, and radiocarbon dates from charcoal and burnt bone placed the first occupation about 47,000 years ago.
“Based on the radiometric dating of various archaeological materials, this site is the earliest long-term home of a high mountain region known to us worldwide,” study author Götz Ossendorf, an archaeologist at the University of Cologne, said, according to swissinfo.ch.
The residents made tools from obsidian found on a ridge a few hundred meters above the shelter and ate mainly giant mole rats, the researchers said. Bones on the shelter floor suggested they sometimes competed with hyenas for the rodents, Ars Technica reported.
Alexander Groos, Heinz Veit and Naki Akçar of the University of Bern dated moraines in several valleys and found that glaciers lay not far from the shelter during the last cold period, about 40,000 years ago. Glacial melt would have supplied fresh water.
Scientists had long assumed that people settled above 2,500 meters relatively recently because high altitude strains the human body. “The most exciting finding is the fact that prehistoric people repeatedly, over millennia, spent considerable amounts of time in high altitudes at a residential site and actively, deliberately made use of the available Afro-alpine resources,” Ossendorf told Live Science.
It is still unclear whether the hunters lived at the shelter permanently, according to the journal.
Sources: Science: Ossendorf et al., “Middle Stone Age foragers resided in high elevations of the glaciated Bale Mountains, Ethiopia” (2019), swissinfo.ch, Ars Technica, Live Science