Both sides of the recent Ethiopian bone hand axe find.

1.4-Million-Year-Old Bone Hand Axe Revises Toolmaking Timeline


In Ethiopia, a team of experts have uncovered a bone hand axe made, a staggering 1.4 million years ago, by an ancestor of modern humans. It was probably made by the archaic human species Homo erectus . The Ethiopian bone hand axe find is unique because it is made from hippopotamus bone and provides a very early example of H. erectus toolmaking capabilities. The find was made by specialists working at the remote Konso-Gardula site, in Ethiopia. This area has yielded a number of tools made by H. erectus .

The archaic H. erectus species of humans appeared over 2 million years ago and were the first to spread beyond Africa to Eurasia. They were the ancestors of Homo Heidelbergensis , who are, in turn, the probable ancestors of modern humans. It is believed that H. erectus were the first hominins to use fire, and develop other early technologies, including tools.

Bone Hand Axe is Only Second of Its Kind

In recent decades, specialists in Africa have uncovered many hand axes that appear to have been made by H. erectus . These early hand axes were made by whittling away flakes from a stone until it was sharp. This method is known to researchers as the ‘ Acheulean technique ’ reports Haaretz. These tools are typically oval-shaped to allow an early human to grasp the axe and one side was sharpened into a pointed blade.

Acheulean hand axes

Acheulean hand axes ( Public domain )

Experts found the 4-inch (12 cm) bone hand axe at the Konso-Gardula site, which was not particularly surprising. However, what was unusual was that it was made from the femur of a Hippopotamus. The researchers wrote in the PNAS Journal that ‘The large number of flake scars and their distribution pattern, together with the high frequency of cone fractures’ indicated that it was made by an early human, almost certainly a H. erectus .

Finding a hand axe made of bone is rare and reports that ‘It represents just the second bone-based H. erectus -made hand axe ever found’. The only other known example, found in Tanzania, was made from an elephant bone .

An analysis of the Ethiopian bone hand axe revealed that is was worn and thus well used. The researchers who unearthed the artifact wrote in PNAS that ‘Edge damage, polish, and striae patterns are consistent with use in longitudinal motions, such as in butchering.’ Moreover, it was almost identical in construction to stone axes from that period.

The biggest outcome of the Ethiopian bone hand axe discovery was how early it was made. Although it is far from the oldest of tools discovered (tools unearthed on the shores of Lake Turkana in Kenya, and date to 3.3 million years ago) researchers stated that it shows H. erectus had command of skills ‘that had only been thought to have developed half a million years later,’ reports Haaretz. Therefore, based on the bone tool find, H. erectus developed sophisticated toolmaking skills much earlier than widely believed.

The bone hand axe (micro-ct based render) shown placed in a hippopotamus femur

The bone hand axe (micro-ct based render) shown placed in a hippopotamus femur (Gen Suwa, University of Tokyo / PNAS)

Bone Hand Axe Shows Better Tool Skills Than Formerly Thought

The early human who made the Ethiopian bone hand axe must have been highly skilled. Tohoku University archaeologist Katsuhiro Sano wrote that, ‘That kind of control is even harder to accomplish with bone than with stone’ according to Ars Technica . It provides a fascinating insight into H. erectus and demonstrates that they had a high level of technical knowledge. Sano wrote that these hominins could understand ‘material properties like sharpness and durability well enough to choose the right material for the right job’ according to Ars Technica .

However, there is one mystery about the find: Why use bone in the first place, since stones are more resilient and stronger? One answer is that hippopotamus bones were readily available and may have been more suitable for some specific task.  At the time, there would have been plenty of hippos in this area, which at the time was a wetland zone. The Ars Technica article suggests that ‘volcanic activity in east Africa sometimes changed hominins’ access to stone deposits for centuries at a time.’ Therefore, early humans in such areas could have been forced to use bones for toolmaking.

Bone Hand Axe Shows Greater Intelligence and Social Skills

The bone hand axe head shows that H. erectus was technologically advanced. Sano and his collaborators believe that the ‘abundance of workable stone around Konso may have helped Acheulean toolmakers there hone their craft since they had plenty of material to work with’ according to Ars Technica . The sophistication of this hand tool shows that H. erectus may have passed on their knowledge of toolmaking. And this suggests that they were smarter and had more developed social structure than previously believed. Sano and his colleagues stated in the Ars Technica article that ‘Our early hominin cousins were already very resourceful, very competent, and very intelligent.’

The Ethiopian bone hand axe discovery is very important. The unearthing of a hand axe made out of a femur bone demonstrates the evolution of archaic humans that lived in the Konso area. In the PNAS article researchers concluded that this find adds considerably to the ‘known technological repertoire of the African Early Pleistocene Homo.’ Work is continuing at the Konso site and more bone hand tools may be unearthed in the future.

Top image: Both sides of the recent Ethiopian bone hand axe find.             Source: Berhane Asfaw, University of Tokyo / PNAS

By Ed Whelan


Katsuhiro Sano et al. A 1.4-million-year-old bone handaxe from Konso, Ethiopia, shows advanced tool technology in the early Acheulean, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2006370117

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