Early humans lived in Ethiopian highlands 2 million years ago
A child’s jawbone found in Ethiopia is one of the earliest fossils identified as Homo erectus, and shows ancient hominins settled in high-altitude areas
By Michael Marshall
12 October 2023
Illustration of a Homo erectus child with her mother in the Ethiopian highlands
Diego Rodriguez Robredo
Ancient humans were living in the highlands of what is now Ethiopia as early as 2 million years ago. A reanalysis of a fossilised jawbone from the region confirms that it belonged to a Homo erectus, and represents the earliest evidence of hominins living in such high-altitude areas.
The highlands represent “a third pole for human evolution in Africa”, says Margherita Mussi of the Italo-Spanish Archaeological Mission at Melka Kunture and Balchit, based in Rome. Hominins have been found in large numbers in eastern and southern Africa, but not to date in upland areas.
Mussi and her colleagues re-examined the lower jawbone of an infant, which was discovered in 1981 at a site called Garba IV in the Ethiopian highlands. Garba IV is one of a cluster of sites known collectively as Melka Kunture. Mussi has nicknamed the jawbone “Little Garba”.
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The jawbone had previously been identified as an early member of the genus Homo, which includes our own species Homo sapiens and several now-extinct groups. However, it wasn’t possible to confidently identify the species.
Mussi and her team used synchrotron imaging to study Little Garba’s teeth, which hadn’t yet erupted from the jawbone. They compared the shape of the teeth to those of multiple hominin species. “The teeth are a very good marker, so we can say for sure this is indeed an early Homo erectus,” says Mussi.
In a previous study published in 2021, Mussi’s team also re-dated the Garba IV site. It consists of layers of sediment laid down over time. In the sediments, the researchers found traces of past shifts in Earth’s magnetic field, which could be matched to similar records elsewhere. Based on this, they conclude that Little Garba is 2 million years old. This makes it one of the oldest H. erectus ever found.
