Neandertals: Ancient Stone Age builders had tech skills

In at least one part of Stone Age Europe, Neandertals were lords of the rings. Neandertals are close evolutionary cousins of modern humans. Some 176,500 years ago, these ancient folk built large, circular structures, researchers now report. Found on the floor of a cave in southern France, the circles had been built from broken-off mounds of minerals. These natural stone mounds are known as stalagmites (Stah-LAG-mytes).

Long ago, Neandertal groups explored the dark recesses of Bruniquel Cave. There, they assembled stalagmite pieces into complex configurations, reports Jacques Jaubert. He is an archaeologist at the University of Bordeaux in France. He and his colleagues described their findings online May 25 in Nature.

Scientists found two ring-shaped formations and four smaller arrangements. All had been built from stalagmites. The circles are situated 336 meters (1,100 feet) inside the cave. All display traces of ancient fires on chunks of stalagmites. 

These ancient constructions were discovered in the early 1990s. However, until 2013, scientists had only limited access to the cave. Jaubert’s team eventually took samples from six stalagmites. They came from the two circular structures. The scientists dated the age of these creations based on the decay of uranium, an element in the samples. Being radioactive, the uranium atoms split into smaller atoms at known rates. With careful measurements and math, scientists can use that knowledge to determine the age of an object like a stalagmite.

Neandertals inhabited Europe and Asia from around 400,000 to 40,000 years ago. The new analyses date the building of the stalagmite circles at around 176,500 years ago. Homo sapiens first evolved during that same time. But our species did not leave Africa until about 60,000 years ago. That leaves Neandertals as the likely builders of the cave circles.

Skilled builders

Neandertals in Europe had notable social behaviors and technical skills. Indeed, some scientists have argued that these traits roughly equaled those of humans living at the same time in Africa. The Bruniquel Cave structures provide further evidence of this, says Jaubert. His group plans to probe whether the cave circles might have been used in rituals or just served some practical purpose.

Additional finds might also point to whether Neandertals regularly made stalagmite caves structures, says Marie Soressi. She wrote a commentary about the new finding in Nature. An archaeologist, she works at Leiden University in the Netherlands.

Jean-Jacques Hublin doesn’t find it surprising that large-brained Neandertals explored caves and assembled structures out of stalagmites. He is a paleoanthropologist. He works at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Neandertals clearly adapted to their environment. Fossil tooth analyses, for instance, indicate that Neandertals altered their diets to exploit different types of foods. This is important because the foods that were available changed over several hundred thousand years. During that time, climates and habitats shifted in Western Eurasia. That altered what plants would grow in areas where Neandertals lived.

Hublin points out that Neandertals still differed from our species in important ways. H. sapiens, for instance, did not alter their diets so much  after leaving Africa, despite moving to new habitats. Members of our species consistently ate many of the same types of edible plants. Hublin suspects that’s because humans made a greater variety of stone tools than Neandertals did. And those tools allowed humans to continue to exploit many of the foods that they preferred.