Researchers investigating a cave in France have identified mysterious stone rings that were probably built by Neanderthals.
The discovery provides yet more evidence that we may have underestimated the capabilities of our evolutionary cousins.
The structures were made from hundreds of stalagmites, the mineral deposits which rise from the floors of caves.
Dating techniques showed that they were broken off 175,000 years ago.
The findings are reported in the journal Nature.
The round structures were discovered in Bruniquel Cave in South-West France. The stalagmites had been chopped to similar lengths and laid out in two oval patterns up to 40cm (16in) high.
“Their presence at 336m from the entrance of the cave indicates that humans from this period had already mastered the underground environment, which can be considered a major step in human modernity,” the researchers write in their study.
Co-author Jacques Jaubert, from the University of Bordeaux, said he had ruled out the possibility that these carefully constructed rings, which show traces of fire, could have come about by chance or have been assembled by animals such as the bears and wolves whose bones were found near the entrance of the cave.
Read more at: http://www.bbc.co.uk/news/science-environment-36381786
SOURCE: www.bbc.co.uk