Known for their protruding brows and stocky build, Neanderthals are often portrayed as a primitive prototype of the modern human. Yet as our understanding of our extinct relative deepens, the image of the Neanderthal has evolved from that of an archaic ape to a surprisingly sophisticated hominid.

What did Neanderthals look like?

Fossil remains reveal some immediately noticeable physical differences between Neanderthals and Homo sapiens. For a start, the ancient species was shorter and broader, with a wider pelvis, heavier bones, and more muscle.

Evolutionary anthropologists have suggested that this thickset build may have enabled Neanderthals to preserve more body heat, helping them survive the frosty Eurasian climate. In contrast, modern humans originating from Africa might have had less need for bulky bodies, thus explaining our flimsier frames.

Other theories propose that Neanderthals’ robust physique may have been an adaptation to hunting large game without sophisticated weaponry, although debates surrounding the evolutionary purpose of this chunkiness remain very much unresolved.

Moving up to the face, and modern humans are clearly distinguishable by their “true” chin - a feature not possessed by ancient hominids. Neanderthals also had significantly larger noses than we do, possibly to help them warm up the cold air they inhaled before it entered the lungs.

Alternatively, these generous honkers might have endowed Neanderthals with a higher respiratory capacity, thus enabling them to power their heavy bodies. Whatever the reason for Neanderthals’ monumental snoots, it’s likely that we inherited some of their large nose genes when our ancient ancestors mated with them, which explains why some modern humans have such tremendous sniffers.

Finally, analysis of Neanderthal teeth has indicated that they probably matured much faster than Homo sapiens do, possibly reaching adulthood at around 15 years of age.

How intelligent were Neanderthals?

The biggest clues as to how we differ from Neanderthals can be found in the shape and size of the skull. Overall, our cranial vault is about the same size as that of our ancient cousins, although while we have a rounded – or globular – braincase, Neanderthals possessed a flatter dome.

This alone doesn’t tell us too much about differences in cognition, although a recent study found that Homo sapiens carry a single genetic mutation that promotes the development of neurons in the prefrontal cortex – the part of the brain responsible for complex thought. Thus, while Neanderthals might have had a slighter larger brain than we do, our superior intelligence may derive from the fact that we have more advanced cerebral hardware.

However, despite the general assumption that Neanderthals weren’t quite as smart as us, there is evidence to suggest they mastered the use of fire, buried their dead and even created art. The so-called Mousterian industry associated with Neanderthals also resembles the stone tools created by early Homo sapiens, although we have, of course, come quite a long way since then, trading the flint scraper for satellites and smartphones.

And while it’s impossible to recreate the behavior of a species that disappeared from the face of the Earth 40,000 years ago, the sequencing of the Neanderthal genome in 2010 revealed that they share about 99.7 percent of their DNA with us. This finding, combined with recent discoveries regarding their ability to cook food, has led to suggestions that they may have been almost as smart as we are.