Traces of “glue” made from birch tar have been found on a stone tool made by Neanderthals 50,000 years ago. Experts say the process could have been widespread. This points to complex thinking and adds to growing evidence that we have underestimated the capabilities of our much-maligned early relatives. The tool was found in the Netherlands, having spent 50,000 years submerged below the North Sea, in conditions which are considered perfect for tar preservation.
Previous finds indicated that Neanderthals may have used birch tar to attach stone tools to wooden handles and the process may have been widespread. However, it appears that this particular tool was a sharp stone flake, which probably had a grip made simply of tar. This would allow the user to apply more pressure with less cutting or damage to hands. Experts think that the tool was probably used either for cutting plant fibres or for scraping animal skins.
This tool was produced by Neanderthals inhabiting the icy tundra, known as Doggerland, a landmass that is now subsumed under the North Sea.
There were relatively few trees and those that existed were small, so collecting the 40kg of wood required for the process, in those conditions was difficult.
There are different known ways to distil the pitch from birch bark. It is interesting that the Neanderthals used the more complex, efficient distillation methods.
Researchers previously thought Neanderthals only hafted (to fix a handle or strap to a cutting edge) certain types of specialised tools, like points and scrapers. This find and a few others from around Europe show that this was not used exclusively for hunting weapons but also for domestic tools as well.
Neanderthal birch tar finds are extremely rare in Europe, yet there are hundreds of Neanderthal sites in the Netherlands. However, this is the first Neanderthal birch tar find of this type in that country.
The new find was discovered on Zandmotor beach near The Hague, where a Neanderthal skull fragment was previously found in the same location.
The earliest known use by Neanderthals of birch tar is in Italy around 200,000 years ago. Modern humans in South Africa are known to have produced adhesives from around 100,000 years ago.
As such finds are only rarely well preserved, there is no definitive proof that there are no older modern human adhesives.
We may never know for sure how long mankind has been using adhesives.