A model of a Neanderthal man, from London's Natural History Museum.
A model of a Neanderthal man, from London’s Natural History Museum. Allan Henderson/CC BY 2.0

Stockier than Homo sapiens, with heavy-set pelvises and barrel-shaped chests, Neanderthals had distinctively shaped skulls that gave them a unique profile. Previous research has suggested that these unique characteristics—sloping cheekbones, protruding faces and noses that might reasonably be described as bulbous—point to a bite so powerful it could be used for gripping, like a third hand. But a new study, published this week in the journal Proceedings of the Royal Society B, suggests an alternative theory: Neanderthals’ facial structure helped them to breathe deeply in cold climates, allowing cold, dry air to move around their nasal passages.

Australian scientists used three-dimensional digital reconstructions of Neanderthals, modern humans, and a third hominid species, Homo heidelbergensis. By running computer simulations to explore the biomechanics of their bites, and how heat flowed through their nasal passages, the team learned that, in fact, Neanderthals seem to have had a bite no stronger than our own, and possibly even weaker. “A surprising result of our simulations was that modern humans can bite hard—and we do it using weaker jaw muscles. Turns out we modern humans are very efficient biters,” Stephen Wroe, lead author of the study, told The Guardian.

But when it came to taking in cold, dry air, and warming and moistening it, Neanderthals had a considerable advantage. The study found that Neanderthal nasal passages were just under 30 percent larger than that of modern humans, perhaps helping them to survive in harsh, frigid conditions.

On top of that, they seem to have had larger nostrils, which allowed them to propel air through those passages more quickly than we can—a possible boon for an active lifestyle, heavy on huffing and puffing. “The calorific demands of Neanderthals were huge compared with ours,” co-author Chris Stringer told The Guardian. “They were moving around a lot, they probably had less efficient clothing and therefore they are having to burn a lot more of their body fat to keep warm.”

While some new research suggests that Neanderthals might have displayed behaviors previously believed to be uniquely human, other papers, such as this one, indicate that they had certain physical traits that were all their own.