Neanderthal Kneeprint Found in Clay at Bruniquel Cave

An impression in clay inside Bruniquel cave in south-west France may be a kneeprint left by a Neanderthal roughly 175,000 years ago. The print lies near circular structures made from broken stalagmites that were discovered in the 1990s and described in a 2016 paper.

The structures sit more than 300 metres inside the cave, where it is completely dark. Traces of fire indicate the area was lit, but researchers have not determined whether the circles served as bases for shelters or had another purpose.

Verheyden at the Royal Belgian Institute of Natural Sciences said the impression has been covered by a thin layer of calcium carbonate, the same material that formed the stalagmites. A bear specialist examined the print and concluded it is not a bear print.

Verheyden and colleagues plan to ask people to kneel in various clays to produce comparison impressions. They are also exploring whether Neanderthal DNA could be recovered from the print through collaboration with Mareike Stahlschmidt at the University of Vienna.

The cave entrance collapsed at least 140,000 years ago and remained sealed until 1990. Radioactive isotope measurements date the breakage of the stalagmites to the same period as the construction of the circles. The largest circle measures about 7 metres in diameter.

Some broken stalagmites exceed 20 centimetres in thickness at the base, making it unlikely that bears created the structures. Verheyden presented the findings on 4 May at a meeting of the European Geosciences Union in Vienna. The team continues to search for additional impressions beneath layers of calcium carbonate on the cave floor.