Neanderthals Used Glue to Make Stone Tools 40,000 Years Ago

Around 40,000 years ago, Neanderthals living in what we now call France crafted tool handles using a special sticky substance. This sticky mix was made from ochre and bitumen, materials they gathered from nearby places.

It is the oldest example of this kind of adhesive found in Europe so far. The discovery sheds light on the intelligence of Neanderthals.

The study, shared in the journal Science Advances, involved experts from New York University, the University of Tübingen, and the National Museums in Berlin.

Finding evidence of ancient glue from a Neanderthal site

Led by Dr. Patrick Schmidt from the University of Tübingen and Dr. Ewa Dutkiewicz from the Museum of Prehistory and Early History at the National Museums in Berlin, a team of researchers took another look at artifacts from the Neanderthal site called Le Moustier in Dordogne. Their goal was to identify any signs of ancient tool glues.

Figuring out how early humans made and used adhesives is important because it gives us solid proof of how their culture and thinking abilities evolved over time.

Humm, Neanderthals using glue? pic.twitter.com/CCwoOoASQy

— AdmiredArt (@admired_art) February 22, 2024

These incredibly well-kept tools reveal a technique that’s quite similar to what early humans in Africa used but with a unique Neanderthal twist, explained Radu Iovita, an associate professor at NYU’s Center for the Study of Human Origins.

The stone tools from Le Moustier are stored in the Museum of Prehistory and Early History collection and hadn’t been thoroughly studied before.

A mixture of ochre and bitumen found on stone tools

The researchers found traces of a mix of ochre and bitumen on various stone tools. These included scrapers, flakes, and blades. Ochre is a natural pigment found in the earth, while bitumen is a component of asphalt that can be found in crude oil or naturally in soil.

Schmidt explained that they were surprised to find that more than half of the mixture was ochre. Normally, air-dried bitumen can stick things together on its own, but it loses its adhesiveness when you add so much ochre.

To confirm this, Schmidt and his team conducted tests to measure how strong the adhesive was and compared it with samples they made in the lab.

When researchers tried using liquid bitumen, it wasn’t great for gluing things together. However, when they added fifty-five percent ochre, it turned into a soft, moldable substance, explained Schmidt.

He said that it’s sticky enough to keep a stone tool in place, but it doesn’t make your hands dirty. This means it is perfect for making handles.

The researchers collaborated with New York University to closely examine the marks of wear and tear on these stone tools under a microscope. They found that the adhesives on the tools from Le Moustier were indeed used in this manner.