Archaeologists have discovered a large haul of discarded cutting tools and animal bones in Ain Boucherit, Algeria, some dating to 2.4 million years ago. Not only does this find contribute considerably to the collection of prehistoric stone tools from this period, but it undermines some of the current theories we have on the origin of humanity.
Up until recently, the oldest stone tools found in North Africa were 1.8 million years old – again, in Algeria. It's thought that the use of such tools gradually spread around the continent from cultures in East Africa (the "garden of Eden"), where they were originally developed.
This theory hinges on the Oldowan tools of Gona in Ethiopia, which are 2.6 million years old and the very oldest stone tools we know of to date. These Oldowan stone artifacts (and those found later) display distinctive markings, or flakes, that give the tools a sharp edge that can be used for cutting.
The tools found in Ain Boucherit contain similar markings and were found alongside 19 animal bones that appear to show indentation marks – an ancient hominin attempt at butchery. But, according to a study published in Science, what makes them really remarkable is their age. If what the researchers say is correct – and some experts not involved in the study have expressed doubts – the oldest in the collection are only 200,000 years younger than the oldest stone tools in the world.
This would mean the use of Oldowan-style tools spread more than 4,800 kilometers (3,000 miles) in a period of just 200,000 years. And while that might seem like an extraordinarily long time, it is nothing evolutionarily speaking.
To date the tools, Mohamed Sahnouni, lead author and an archaeologist at Spain’s National Research Center for Human Evolution, and his team used three methods. These include magnetostratigraphy and Electron Spin Resonance (ESR) dating. They also analyzed the animal bones found alongside the tools, identifying species of now extinct elephants, mastodons, horses, and pigs as well as antelopes, rhinos, hyenas, and crocodiles.
The results of the analyses reveal the tools in the collection are between 1.9 and 2.4 million years old.
Sahnouni proposes two explanations. Either this proves there was a rapid dissemination of stone tools from East Africa to places outside the area or it shows that early hominins developed the use of stone tools in multiple locations independently – a conclusion that is not entirely inconsistent with previous studies suggesting hominids migrated further and earlier than conventional theories put forward.
But there is something else to consider. In 2010, at a site in Dikika, Ethiopia, a team of archaeologists discovered 3.4-million-year-old bones they say contain indentations created by stone tools. Others have disputed the claim but if they are right, it pushes the timeline back once again. It would mean the original theory – that East Africa was the hub of tool innovation – holds true, it's just that it was taking place earlier than we thought.
In both cases, more research is needed to confirm these new claims.