Acheulean technologies, the longest-lasting tool-making in prehistory, first appeared 1.75 million years ago in easter Africa and persisted until 1.2 million years ago in India. It is characterized by the production of large bifacial tools, such as cleavers and stone handaxes.

Phys.org reported that new research from scientists at Max Planck Institute for the Science of Human History re-examined an Acheulean site at the margins of the monsoon zone in the Thar Desert, India. They reveal that Acheulean populations must have persisted until 177,000 years ago, just before Homo sapiens arrived.

Acheulean Tool-Making Tradition May Have Persisted Until About 177,000 Years Ago Before Homo Sapiens Arrived
(Photo: Wikimedia Commons)
A photograph of the upper pre-historic archeological site at the Kariandusi Museum in Kenya. The photograph is of the extensive collection of Acheulean hand-axes excavated by Louis Leakey in 1928. The hand-axes are from the Lower Paleolithic era and are made from both obsidian and trachyte.

World's Youngest Acheulean Sites

In a paper titled "Constraining the Chronology and Ecology of Late Acheulean and Middle Palaeolithic Occupations at the Margins of the Monsoon" published in Scientific Reports, researchers reported the recent occupation of Acheulean populations in the site of Singi Talav up to 177,000 years ago.

It turns out that this is the youngest site of Acheulean populations in India. South Asia has been known before as the home of the world's youngest Acheulean sites, but this discovery opens a new understanding of the earliest expansions of Homo sapiens across Asia.

Singi Talav is located in a lakeside close to the modern town of Didwana at the monsoon zone of the Thar Desert, where multiple stone tools were discovered in the early 1980s. Since then, several Acheulean sites have been examined to determine the dates of Acheulean occupations in India. However, the techniques needed to accurately date the discoveries were inadequate at that time, so they remain poorly known.

Study lead author Dr. Jimbob Blinkhorn said that the lakeside site has ideal preservation conditions for an archaeological site, which allowed scientists to return after three decades since it was first excavated. They used modern methods to re-examine the site, such as luminescence methods and new approaches to date the Acheulean occupation.

These methods allowed them to determine the last time sediments were exposed to light to understand when ancient humans lived in the area and created the stone tools. They were also able to compare it to other sites across the region.

Studying the Ecology of an Acheulean Site in India

The Thar Desert is located at the western edge of the modern Indian monsoon system. According to Britannica, the subtropical climate in the desert resulted from persistent high pressure and the site's subsidence. The southwest monsoon winds bring rain during summer, but it tends to bypass the desert to the east.

As Phys.org reported, researchers believe that the summer monsoon system of that site may have allowed ancient humans to thrive, although it might have fluctuated significantly. Researchers examined phytoliths and soil geochemistry to reveal the site's ecology when Acheulean stone tools were made.

This is the first time that the ecology of an Acheulean site in India has been examined with modern techniques to reveal a broader character of the landscape where ancient humans might live.

They noted that their findings support evidence from across the region that the youngest Acheulean populations of the world are in India, which persisted until Homo sapiens appeared and expanded across Asia. The Thar Desert most likely became a key ecological frontier for Homo sapiens to expand their populations and meet other populations.