Neanderthals built underground structures

In the Bruniquel cave in Tarn-et-Garonne, Neanderthals constructed two circles of stalagmites approximately 336 meters underground around 176,500 years ago, about 130,000 years before the arrival of Homo sapiens in Europe.

Discovery and research history

The discovery was made by Bruno Kowalczewski in 1990, and later studied by François Rouzaud, whose disappearance halted research until Jacques Jaubert of the University of Bordeaux, along with Sophie Verheyden of the Royal Institute of Natural Sciences in Belgium and Dominique Genty of CNRS, resumed the investigation.

Details of the structures

Their findings, published in the journal Nature in 2016, revealed two annular structures composed of 400 stalagmite fragments, totaling 2.2 tonnes, arranged in organized patterns.

Dating the structures

The structures were dated using uranium-thorium analysis of calcite, which determined their age with a margin of error of only 2,000 years. The absence of bones, tools, or hearths in the cave posed a challenge for traditional dating methods, but the calcite layers provided a reliable timeframe.

Preservation and significance

The site is now classified as a historical monument, though access remains restricted to preserve the integrity of the findings. The exact function of the structures remains unknown, with hypotheses ranging from ritual use to temporary shelter or territorial marking.

Impact on understanding Neanderthals

The discovery has significantly altered the understanding of Neanderthal capabilities, demonstrating their ability to organize and plan in complex ways previously attributed only to Homo sapiens.