Ancient ring-like structures found in a cave in France were probably built by Neanderthals, a study published online in Nature this week indicates. The construction and location of the rings, along with traces of fire activity, seem to indicate that the builders had more complex behaviours than previously attributed to Neanderthals.
Structures made from about 400 pieces of stalagmites were discovered 336 metres from the entrance of Bruniquel Cave in southwest France in 1992, but remained mostly unstudied until recently. Two of the structures that are ring-shaped (2.2 x 2.1 metres and 6.7 x 4.5 metres in size) are dated to around 176,000 years ago, which coincides with the period when Neanderthals were in that part of Europe, Jacques Jaubert and colleagues report.
The rings are made with similarly sized pieces indicating that their construction was carefully planned, although the functions of these structures remain uncertain. Whether they formed part of a refuge or had a symbolic meaning are among the hypotheses that the authors hope to test in their ongoing studies. However, the presence of these structures in the dark depths of the cave indicates that human ancestors had already mastered the underground environment during this period, a modern behaviour that seems to have emerged earlier than previously thought.