A rock overhang at almost 3500 meters in today’s Ethiopia was permanently settled by Stone Age hunters over 40,000 years ago – making it the oldest known prehistoric dwelling in a high mountain range. This is according to a new study published in the journal Science.
The Bale Mountains are a mountain range in southern Ethiopia whose peaks reach heights of up to 4300 meters. This large Afro-alpine ecosystem is considered relatively pristine; the mountains were believed to have only recently been colonized. However, according to a new study conducted by an international and interdisciplinary research group, hunters settled permanently in this area during the last glacial period some 40,000 years ago. By analyzing the environmental and climatic conditions in the region, experts in archeology, soil science, geography, geology, and biology were able to prove that glaciers were located near the former settlement area in the Bale Mountains. The research team was also able to show, based on archaeological discoveries, that these Stone Age settlers made obsidian tools and fed on giant mole-rats.
Bone and Coal Remains
In the Bale Mountains, at an altitude of almost 3500 meters, is a rock shelter known as Fincha Habera. There, the researchers found a variety of archaeological remains, including stone age bone and charcoal residues. “Based on the radiometric dating of a variety of archaeological materials, this site is the earliest long-term habitation of a high mountain region known to us worldwide,” said archaeologist and lead author of the study Götz Ossendorf, University of Cologne. The dating of these finds indicates the repeated colonization of the shelter 47,000 to 31,000 years ago. Thus far, a permanent and intensive colonization at a high altitude has not been documented worldwide.
Sanetti Plateau in the Bale Mountains, Ethiopia (Image: Rod Waddington).
Reconstructing Climatic Conditions
Researchers Alexander Groos, Prof. Heinz Veit, and Dr. med. Naki Akçar of the University of Bern reconstructed the Stone Age environmental and climatic conditions near the site. “Despite their height, the Bale Mountains are now unglaciated,” explains Groos, who is investigating the climatic and landscape history of the high mountains as part of his dissertation. “Moraine ramparts and other glacial legacies, however, indicate that the Ethiopian highlands were heavily glaciated during the last glacial period.”
Rock samples taken from moraines in several valleys in the Bale Mountains were analyzed and dated to determine the exact time of the different glaciation phases. “Our results show that about 40,000 years ago it was colder than it is today in the Bale Mountains, and that Stone Age hunters lived close to the glaciers,” says Groos.
Obsidian Tools
Researchers also explored questions regarding how people handled conditions during the last glacial period, and how they shaped their habitat. During excavations and terrain surveys, the team identified five places at 4200 meters above sea level where obsidian was recovered. People in the Stone Age used this volcanic rock glass to make sharp-edged tools. In the area, the researchers unearthed numerous stone artefacts that have been processed by humans and that further demonstrate the mining of obsidian.
Giant mole-rat (Tachyoryctes macrocephalus) photographed on the Sanetti Plateau in the Bale Mountains, Ethiopia (Image: Charles J. Sharp).
Giant Mole-Rats as a Staple Food
Another important resource for the Stone Age hunters was the endemic giant mole-rat, which served as food for hunters during the last glacial period. Only occuring in the Bale Mountains, the giant mole-rat and could be hunted year-round. These findings from the Ethiopian highlands, gained in the framework of interdisciplinary cooperation, show that Stone Age hunters used available resources intelligently and adapted their behavior to meet and overcome the challenges of life in the high mountains.
A German only version of this press release can be found on the University of Bern website.
Read More: Ossendorf G. et al. ‘Middle Stone Age foragers resided in high elevations of the glaciated Bale Mountains, Ethiopia.’ Science, August 9, 2019. DOI: 10.1126/science.aaw8942
Cover Image: Richard Mortel, Sanetti Plateau, Bale Mountains National Park, CC BY 2.0.