“This discovery provides clear evidence that Neanderthals had fully human capabilities in the planning and the construction of ‘stone’ structures, and that some of them penetrated deep into caves, where artificial lighting would have been essential,” Chris Stringer, a paleoanthropologist at the Natural History Museum in London who was not involved in the study, told National Geographic.
“The big question is why they made it,” Jean-Jacques Hublin, a palaeoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who also did not participate in the study, told Nature. “Some people will come up with interpretations of ritual or religion or symbolism. Why not? But how to prove it?”
University of Bordeaux archaeologist Jaque Jaubert and his coauthors recently revisited the structures, which were first discovered in the early 1990s. Armed with enhanced methods of dating the materials in the cave, Jaubert and his team analyzed the stalagmite circles—some as deep as 336 meters beyond the cave entrance and as large as 7 meters in diameter—and found that they were constructed between 174,400 and 178,600 years ago. The feat required complex planning and coordination, the authors suggest, because the structures are 50 centimeters high in spots and are made from hundreds of stalagmites weighing several tons in total. “That must take time,” Jauber told New Scientist.
In addition to the complex logistics involved in constructing the circles, the Neanderthal builders likely toiled by torchlight. This indicates “that humans from this period had already mastered the underground environment, which can be considered a major step in human modernity,” the authors wrote in the paper.