Old-school adhesives: Archeologists discover some of the earliest known examples of adhesive use in Italian cave

In a pair of caves known as the Grotta del Fossellone and the Grotta di Sant’Agostino in Italy’s western Lazio region, archaeologists discovered some of the earliest known examples of the use of adhesives.

In this study, published in the journal PLOS ONE, archaeologists found evidence that Neanderthals that lived around 55 to 40 thousand years ago ventured out of their caves to collect resin from pine trees. Then, they used the resin as an adhesive to glue together their stone tools to handles made out of either wood or bone. This process is known as hafting and it is an important milestone in the development of technology. It signified the progression from simple to more complex forms of tool-making.

Furthermore, the findings represent another piece in a growing body of evidence that says that Neanderthals were a lot more intelligent than common understanding suggests. (Related: Re-imagining cave men: New research finds that Neanderthals were not hunchbacks.)

Resin and beeswax

The Grotta del Fossellone and the Grotta di Sant’Agostino were home to groups of Neanderthals that lived there sometime during the Middle Paleolithic period, thousands of years before Homo sapiens even set foot on Europe. From these two sites alone, archaeologists were able to discover over a thousand different stone tool artifacts.

In the study, the researchers noticed some kind of material on several of the tools. They were uncertain whether it was simply inorganic sediment or traces of adhesives. To figure out what it was, lead author Ilaria Degano of the University of Pisa conducted a chemical analysis on several of the artifacts using a process known as gas chromatography/mass spectrometry.

The results of the analysis showed that the stone tools did have traces of adhesive on them. Not only were they coated with resin from pine trees, but in one case the Neanderthals even used beeswax as a glue. Mixing beeswax with resin makes for an even stronger adhesive, and other archaeological sites have also found evidence that beeswax and resin were combined. This suggests that the Neanderthals understood that the combination made their tools last longer.

The researchers said that these findings show that Italian Neanderthals were more advanced since they had the understanding that attaching a handle to their tools made them easier to use. While the artifacts found in the Grotta del Fossellone and the Grotta di Sant’Agostino are not the oldest known examples of hafting by Neanderthals, it does show that the technology was more common than previously believed.

The brilliance of the Neanderthals

The researchers believe that this also provides evidence that Neanderthals knew how to build fires whenever they needed. Pine resin dries up quickly when exposed to air, suggesting that the Neanderthals would have had to heat it up in order to make an effective glue. This hypothesis is backed up by the fact that the archaeologists found traces of both charcoal and an ancient fireplace at the Grotta del Fossellone.

Furthermore, this suggests that the fires could have also been used not just to haft new tools, but also to work on existing ones. A tool found in the Grotta di Sant’Agostino had resin on its scraping edge. The researchers suggest that the scraper was used to catch melted resin while hafting or possibly re-hafting a tool.

“We continue to find evidence that the Neanderthals were not inferior primitives but were quite capable of doing things that have traditionally only been attributed to modern humans,” said Paola Villa, co-author of the study and adjunct curator at the University of Colorado Boulder’s Museum of Natural History.

Sources include:

ScienceDaily.com

ArsTechnica.com