Ice Age hunter-gatherers reached Italy about 30,000 years ago, around 2,000 years earlier than archaeologists had previously thought, according to a new study of a rock shelter on the French-Italian border. The finding rewrites the timetable for one of the great population movements of prehistoric Europe.

The evidence comes from Riparo Mochi, a rock shelter in the Balzi Rossi complex at Ventimiglia, on the Italian Riviera. A fresh excavation of the site uncovered an intact ancient hearth surrounded by marine shells and stone tools. A tiny marine shell from the sediment around the hearth was radiocarbon dated to between 30,800 and 29,900 years ago, making Riparo Mochi the earliest recorded site of Noaillian occupation in Italy.

The shell that reset the timeline

The study, published in the Journal of Archaeological Science: Reports by Fabio Santaniello and colleagues from the University of Trento and the University of Pisa, focused on the Noaillian, a regional variant of the Gravettian culture of Upper Palaeolithic hunter-gatherers. The Noaillian is recognised by its characteristic stone tools, above all the Noailles burin, a small, specialised cutting tool.

Archaeologists had long believed the Noaillian spread steadily from west to east, from northern Spain and France into Italy along the narrow coastal corridor where Riparo Mochi sits. But the dates did not fit. The culture appeared in southern Italy as early as 31,000 to 30,000 years ago, while at Riparo Mochi, much closer to France and on the supposed entry route, it seemed to have arrived only around 28,000 years ago.

The new date closes most of that gap. The shell, from a tiny marine snail of the genus Bittium, was taken from the ash and silt around the hearth and dated at the University of Vienna. Charcoal collected from the hearth itself could not be used, because the samples were stolen before they could be analysed. Once the marine reservoir effect was corrected for, the shell gave an age of 27,003 radiocarbon years, calibrating to 30,802 to 29,901 calendar years ago.

How the tools were really used

The excavation also changed what researchers think about the tools themselves. The team examined more than 7,500 tiny stone artefacts, including cores, blades and waste chips, found around the hearth and neighbouring layers, mapping the exact three-dimensional position of each one and water-sieving all the soil through a fine mesh.

Microscopic wear analysis showed that the Noailles burins were not used to engrave hard materials such as bone and antler, as archaeologists had long assumed. No wear was found on their pointed chisel tips. Instead, wear along their long, razor-sharp side edges showed they were used to cut soft animal tissues, including meat and skin. Other tools had different jobs: microgravettes were fitted onto shafts as tips for hunting weapons, while scrapers and wedges were used to shape wooden shafts and to split bone, either to reach the marrow or to make blanks for bone tools.

A migration, not just an idea

The authors fed the new date into a statistical model built from 54 screened radiocarbon dates from across western Europe. The model traces the Noaillian from northern Spain around 34,000 years ago, through the Pyrenees around 32,000 years ago and Aquitaine around 31,000 years ago, reaching Italy around 30,900 years ago. The tradition as a whole spans roughly 33,000 to 26,000 years ago.

The researchers suggest the Noaillian arrived as a complete way of life, rapidly replacing existing local patterns rather than blending with them. That points to an expansion driven by actual human migration into sparsely populated coastal lands, rather than the spread of ideas through trade alone.

The arrival at Riparo Mochi coincided with Greenland Stadial 5.1, around 30,500 years ago, when Europe's climate turned suddenly cold and dry. The harsh conditions are likely to have pushed people eastwards along the Mediterranean coast, towards milder refuges in Italy.

Much of what was known about Riparo Mochi came from excavations carried out between 1938 and 1959, when fine sediments were rarely sieved and layers were removed in broad artificial levels. The new work, using modern methods that follow the natural boundaries of the soil, shows how much a fresh look at a familiar site can still reveal about the first hunter-gatherers to cross into Italy.