Researchers have unearthed some deliberately sharpened tools that date from over 2.5 million years ago. These artifacts are changing our understanding of the invention of tools and showing that our ancestors may have used a variety of basic technologies. They are also demonstrating that our early ancestors may have invented stone tools separately and repeatedly before they became widespread.

The find was made by a team of international and local experts, at the Bokol Dara site, in northern Ethiopia. In total, over 320 stone tools and weapons were uncovered. According to the Phys.org, they have been found, “close to the 2013 discovery of the oldest fossil attributed to our genus, Homo discovered at Ledi-Geraru.”

Stone Tools Used by Our Earliest Ancestor

The artifacts were found after a dig by hand on a steep slope in semi-desert. They are well-preserved because they were apparently discarded by early members of our genus by the side of a spring or lake. This body of water dried up and sediment covered the tools and weapons. The Independent quotes Vera Aldeias from the University of Algarve as saying that as a result “the site then stayed that way for millions of years.”

The stone tools were found near the oldest fossil attributed to the genus Homo. ( David R. Braun )

Flaked Stone Tools - Over 2.5 Million Years Old

Experts were able to accurately date the tools to between 2.58 and 2.61 million years ago. They were able to do this because they could date a layer of volcanic ash under the tools and other stone artifacts. This dating was then confirmed “magnetic signature of the site's sediments” according to Phys.org. This means that the tools were the oldest sharpened tools yet found. They are approximately 10,000 years older than the previous oldest that was found in Gona, Ethiopia.

The tools were made by chipping flakes off a stone that could be held in the hand. They usually were made by chipping off just a few flakes and were mainly used for the cutting of animal carcasses into the meat.

According to the New Scientist , “the style of the artifacts classifies them as Oldowan stone tools.” These were among the first tools that were capable of cutting and are different from the percussion tools, used by both early hominids and indeed primates. The stone artifacts were examined by a team from Arizona State University and George Washington University.

Blade Engda of the University of Poitiers lifts an artifact from 2.6 million year old sediment exposing an imprint of the artifact on the ancient surface below. ( David R. Braun )

Stone Tools Invented Independently

The researchers found that the tools were very primitive and crude. The New Scientist quotes David Braun, one of the team members as stating that the artifacts had “significantly lower numbers of actual pieces chipped off a cobble than we see in any other assemblage later on.” This suggests that the makers were not as skilled or that they were not aware of more sophisticated stone tools produced in other areas.

This indicates to many that tools were developed by many groups and they may even have been re-invented several times. As a result, rather than seeing hominids learning tool-use from one group, they may have developed them independently, suggesting a great deal of ‘technological diversity’ among our early ancestors according to Phys.org.

A Technological Revolution

The stone artifacts found do not seem to have any connection to the so-called ‘Lomekwian tools’. These are tools used for banging and smashing items and are still used by chimpanzees in the jungle. It is something of a mystery as to how hominids transitioned from simple percussive tools to cutters and knives.

Eventually, the Oldowan sharpened tools were adopted by the general hominid populations. Tools became an integral part of their survival kit. The Oldowan style of stone tools became standardized over time and was then in general use for hundreds of thousands of years.

Oldowan choppers, stone tools dating to 1.7 million years BC, from Melka Kunture, Ethiopia. (Archaeodontosaurus / CC BY-SA 4.0 )

The discovery of the flaked tools in Afer is of great significance because the style of tools is linked to a dramatic environmental shift. According to PNAS.org “the production of Oldowan stone artifacts appears to mark a systematic shift in tool manufacture that occurs at a time of major environmental changes. It is believed that these styles of tools helped humans to adapt to profound changes, as their environment changed from forest to one that was similar to a Savannah. These tools actually changed humans.” This is seen in the reduction in the size of our ancestor's teeth . Because they could cut-up their meat they did not need large teeth.

The find of the flaked artifacts is very significant. It is pushing back the date when our ancestors used more sophisticated cutting tools, which was very important in our evolution. It is demonstrating that our ancestors may have developed tools independently and may have had to re-invent them more than once. This is allowing us an insight into the world of our early ancestors. It is hoped that more tools and stone artifacts will soon come to light. The findings are going to be published in an upcoming edition of the Proceedings of the National Academy of Sciences.

Artistic interpretation of a female at the time of the emergence of Oldowan stone tools. (Esv / Public Domain )

Top image: Researchers found the collection of ‘Oldowan’ flaked stone tools in the Afar region of north-eastern Ethiopia. Source: Erin DiMaggio .

By Ed Whelan