Neanderthals lived on Earth for approximately 250,000 years before they died out, leaving behind their bones, art, and traces of their DNA in living humans today. Before anatomically modern humans left Africa, Neanderthals were already living across Europe and the Middle East — a move that forced their bodies to adapt to frigid, ice age habitats. While scientists have known shorter, stockier bodies helped them survive the cold, another body part has emerged as a key tool for survival: a nose that could “turbo” breath.

Why the Neanderthal face looks so different than our own has been a point of debate among scientists: They were equipped with a large brow ridge, protruding jaws, and big noses. It’s been theorized that their faces evolved this way to have an improved ability to bite or to better warm the cold air with their nose, but an international team of scientists write in a paper released Wednesday in the Proceedings of the Royal Society B that this isn’t the case. The distinctive Neanderthal face they write, adapted to “facilitate greater ventilatory demands” — a schnoz that allowed them to breathe in by up to twice that of modern humans.

Virtual reconstruction of a Neanderthal skull.

The study authors assert that: “Neanderthal facial morphology evolved to reflect improved capacities to better condition cold, dry air, and, to move greater air volumes in responses to higher energetic requirements.” They came to this conclusion by using computer modeling to compare Neanderthal skulls to those of modern humans and another ancient hominin called Homo heidelbergensis, applying finite-element analysis and computational fluid dynamics to the skull models. They determined that both modern humans and Neanderthals were better evolved to condition the air around them with their nose than H. heildebergensis, and that Neanderthals did not have a mechanical advantage over modern humans when it came to biting.

The most important difference, they discovered, was that the Neanderthal’s nasal passage — which was 29 percent larger than Homo sapiens — allowed them to inhale significantly more air than either of the other hominins. This ability to absorb more oxygen, they reason, was an adaptation to the cold that allowed them to make up for energy lost living in such an extreme environment.

For example, people living today are told they need 2,500 daily calories to have the energy they need to thrive. Neanderthals, meanwhile, are assumed to have needed 4,480 calories per day to survive. In turn, a high-calorie diet requires more oxygen to burn the sugars, fats, and proteins that turn into energy.

It’s reasoned that it’s big nostrils and what the scientists call “turbo breathing” that allowed for this necessary increase in oxygen. Barrel-chested neanderthals were running around sub-zero tundra wearing loosely-scrapped together furs — in order to live that lifestyle, they needed to be able to take mega-whiffs.