Neandertal ancestor? Ancient skulls suggest a long path to Neandertals

A clutch of skulls found deep inside a Spanish cave look a lot like Neandertals, an ancient humanlike species. But the shape of these skulls is not quite what scientists would expect from a Neandertal. Such a mix of features suggests that this species, which lived long before Neandertals, was related to them. The new findings also suggest Neandertals went through a long and complicated evolution.

The oldest known true Neandertals lived about 200,000 years ago. (The oldest human remains, for comparison, also date back some 200,000 years.) The 17 skulls analyzed for the new study came from far more ancient hominids: These pre-human folk lived roughly 430,000 years ago. Their skulls provide the oldest evidence of Neandertal-like features, says Juan Luis Arsuaga. This paleontologist led the new study. He works at Complutense University of Madrid, in Spain.

The newfound skulls had protruding teeth and no chin. Those Neandertal-like features suggest these ancient folk used their mouths — like tools — to hold onto things. This ability may have been important to the survival of Neandertals, Arsuaga toldScience News. He and his coworkers describe their findings in the June 20 Science.

Like all living things, Neandertals evolved from an earlier species. That means they changed, probably slowly, over long stretches of time. The skulls in Spain came from a species that lived long before proper Neandertals — but they probably had a common ancient ancestor. The new study suggests that the Neandertal species evolved through many twists and turns. The newly analyzed skulls belonged to one species that popped up during that evolution.

Indeed, the skulls that ended up in a Spanish cave may have come from one of many species that arose and went extinct long before true Neandertals, says Jean-Jacques Hublin.  An anthropologist not involved in the new study, he works at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. 

The brain case — the rear part of the skull that holds the brain — was rather small in the 430,000-year-old folk, says Hublin. Both humans and Neandertals have large brain cases. The newly analyzed skulls suggest that humans and Neandertals may have evolved their big brains in different ways, Hublin says. Over time, those differences may have led humans to success — and Neandertals to extinction.

Arsuaga says the bones raise other questions, too. They showed up at a site now called Sima de los Huesos, or “pit of bones.”  But scientists don’t know how the ancient bones got there.

No populations as old as these pre-Neandertals are known to have practiced end-of-life rituals, such as burying their dead, Arsuaga points out. So how did these ancient bones end up in a Spanish cave? “Someone, some agent had to put them there,” he told Science News. But who or what is responsible? That, he says, is “a problem that is very difficult to solve.”