The Oldowan and the Acheulean — currently the two oldest, well-documented stone tool technologies known to archaeologists — are roughly 30,000 to 60,000 years older than current evidence suggests, according to a new modeling study.
Early stone tool technologies, such as the Oldowan and Acheulean, allowed early human ancestors to access new food types. They also increased the ease of producing wooden tools or processing animal carcasses.
The Oldowan is the oldest-known stone tool industry. Dating as far back as 2.6 million years ago, these tools were likely manufactured by Homo habilis. First discovered at Olduvai Gorge in Tanzania, Oldowan artifacts have been recovered from several sites in eastern, central, and southern Africa. Acheulean stone tools, named after the site of St. Acheul in France where the artifacts from this tradition were first discovered in 1847, were likely produced by Homo erectus.
The earliest known Acheulean tools from Africa have been dated to over 1.7 million years ago.
“Our research provides the best possible estimates for understanding when hominins first produced these stone tool types,” said Dr. Alastair Key, a researcher in the School of Anthropology and Conservation at the University of Kent. “This is important for multiple reasons, but for me at least, it is most exciting because it highlights that there are likely to be substantial portions of the artifact record waiting to be discovered.”In the study, Dr. Key and colleagues used statistical modeling techniques only recently introduced to archaeological science.
The models estimated that Oldowan stone tools originated 2.617-2.644 million years ago, between 36,000 and 63,000 years earlier than current evidence.The Acheulean’s origin was pushed back further by at least 55,000 years to 1.815-1.823 million years ago.
“The optimal linear estimation (OLE) modeling technique was originally developed by myself and a colleague to date extinctions,” said Dr. David Roberts, also from the School of Anthropology and Conservation at the University of Kent.“It has proved to be a reliable method of inferring the timing of species extinction and is based on the timings of last sightings, and so to apply it to the first sightings of archaeological artifacts was another exciting breakthrough.”
“It is our hope that the technique will be used more widely within archaeology.” “Although it is widely assumed that older stone tool sites do exist and are waiting to be discovered, this study provides the first quantitative data predicting just how old these yet-to-be-discovered sites may be.”