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.