An exhibit shows the life of a neanderthal family. (Nikola Solic/Reuters)

For a group that has been extinct for tens of thousands of years, Neanderthals have managed to stir plenty of modern-day controversy.

Despite discovering their remains and tools at countless sites, scientists can't quite decide to what degree the species (or sub-species!) spoke language, commingled with modern humans, or even when exactly they died out.

In other words, the evidence isn't conclusive as to whether they were more like inarticulate cavemen or Fred Flintstone.

Depending on who you ask, "sometimes they're absolute brutes that have nothing to do with humanity," said Shannon McPherron, a researcher at the Max Planck Institute. "And other times you put a suit and a hat on a Neanderthal and they could slip on the New York subway train and be unnoticed."

McPherron, along with researchers at Leiden University in the Netherlands, is now further stoking the Neanderthal debate with his latest finding. At two separate sites near the Dordogne river in southwest France, the researchers discovered Paleolithic lissoirs, or smoothing tools fashioned out of rib bones -- the earliest findings that the Neanderthals used bones in such a sophisticated way.

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The researchers aren't sure which animal these were fashioned from -- likely a deer or something similar -- but these lissoirs were probably used to smooth out and shape animal skins in order to make them more supple and waterproof. Kind of like a prehistoric rolling pin for rawhide. 

The tools are so advanced that when the researchers contacted the Hermès store in Paris, they said their leather workers use a similar tool on the company's luxury goods.

Of course, these aren't the first (or even necessarily the earliest) Neanderthal bone tools to ever have been unearthed. But it is the earliest evidence that Neanderthals used bone in a way that takes advantage of its specific, bone-like properties, such as its pliability.

"Previously, what we found is that they would see bone as just another kind of material that they could work, like bone scrapers, bone notch tools, and hand axes," said McPherron. "What's different here is that they're using this other approach to bone: grinding, polishing, and utilizing the fact that it's pliable."

So what does it mean if the Neanderthals were such deft bone-whittlers? Well, one theory is that modern humans mixed with Neanderthals earlier than previously thought, and humans might have taught them their craftsmanly ways. Or, it might mean that Neanderthals reached this level of ingenuity on their own -- and possibly that they even taught modern humans a thing or two about bone-shaping. It would be, in other words, another point for the subway-riding theory of Neanderthal-ology.