Scientists may have made a key discovery in how Neanderthals were different from modern humans and may have even showed them how to make various tools, Discovery News reported.

Neanderthals were at one point the closest living relatives to modern humans, but they are believed to have gone extinct some 40,000 years ago. They had supposedly dwelled across Europe, the Middle East and Western Asia.

Neanderthals began creating small tools, like body ornaments or small blades, around the time modern humans started to inhabit Europe. The debate surrounding Neanderthals is whether they began developing these tools before or after first contact with modern humans.

"There is a huge debate about how different Neanderthals were from modern humans," said co-author Shannon McPherron, an archaeologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The study, published in the Proceedings of the National Academy of Sciences, analyzed artifacts about 50,000 years old found in two different locations in France, CNN reported.

"Here we have just Neanderthal deposits, and so we can rule out any contamination from later time period deposits," McPherron said.

The two locations, one at a cave called Pech-de-l'Aze, and a valley called Abri Peyrony, yielded fragments and complete bone tool samples, as well as a full Neanderthal child's skull.

Previous discoveries of Neanderthal bone tools did little to distinguish them from stone tools by not distinctly using the properties of the bones.

"This paper adds further evidence that during their final 20,000 years, the Neanderthals displayed aspects of behavioral complexity that we normally associate with modern humans," said Chris Stringer at the Natural History Museum in London, who was not involved in the study.

McPherron said one tool looks very similar to a lissoir, which means, "to make smooth." As the translation implies, it is a tool used to smooth out a hide, making the leather easier to work with and more water-resistant.

After initial testing, the researchers believe the Neanderthal tool was used for a similar purpose. Such a task, however, will require a study of its own, McPherron said.

"A whole study has to be done to actually demonstrate that that's what they were used for," he said.