A collection of broken wooden tools unearthed in southern Italy offers new evidence that Neanderthals used fire to shape wooden tools as early as the Middle Paleocene, about 171,000 years ago. The find sheds important new light on the earliest use of fire, and it reveals how sophisticated Neanderthal technology was. The tools, called digging sticks, are still in use today.

If you’re a hunter-gatherer, the digging stick is your version of the Swiss Army knife for foraging: about a meter long, with one end rounded to offer a handle and the other tapered into a blunt almost-point. They’re useful for digging up roots and tubers, hunting burrowing animals, or pounding and grinding herbs. And the Neanderthals of Middle Pleistocene Italy created and used digging sticks that would be perfectly familiar to modern members of the Australian Bindibu people, the Hadza people of Tanzania, and the San people of southern Africa.

Broken tools

Wood is a popular material for tools in modern hunter-gatherer societies, mostly because it’s available and relatively easy to work with. Archaeologists assume early humans, including Neanderthals, must have used it as well.

“It could be supposed that simple wood or bone objects were the first artifacts created and used by early human ancestors, long before the earliest preserved artifacts, stone tools,” said archaeologist Biancamaria Arunguren. But we don’t have much actual evidence for how early humans used wood, because, unlike stone or bone, wood tends to decay after thousands of years in the ground.

That’s what makes the new find so rare. Archaeologists unearthed pieces of several wooden digging sticks from a site in Tuscany called Poggetti Vecchi.

The site is a plain at the foot of a low hill, near some warm springs. One hundred and seventy-one thousand years ago, grasslands and marshes surrounded the shore of a lake here, according to lake sediments and pollen analysis. Those grasslands were home to large grazing mammals, including straight-tusked elephants known to science as Palaeolaxodon antiquus, the bones of which litter the site.

Artifacts here date to a period when Neanderthals roamed the hills of southern Italy. Archaeologists excavating the site in 2012 found 39 broken pieces of the sticks, along with an assortment of stone tools. Of the 39 fragments, only about four pointed tips and six rounded handles survived, along with 31 pieces of shafts. Four of the handles and all of the tips had been broken during the tools’ lifetimes. And the digging sticks weren’t well-preserved—microscopy showed that bacteria had eaten away at the cell walls of the wood, for instance. But poor preservation is better than no preservation, and the broken bits of wood had plenty to tell archaeologists.

Shaped by fire

Researchers noticed that one of the digging sticks had a 1mm-thick layer of black film on its shaft, and its surface was fractured in a square-like pattern reminiscent of charring. Chemical testing revealed that the wood had, in fact, been charred, and so had 11 of the other finds. This must have been deliberate, because they were all charred evenly, with a thin film, and on the same part of the stick. That implies carefully controlled exposure to a flame.

Archaeologists say that the Neanderthals probably used fire to char the surface of the wood to make it easier to scrape off the bark and shape the ends. Boxwood is one of the strongest European hardwoods, which makes it perfect for a durable tool like a digging stick, but it’s also hard to whittle into shape with stone tools. Fire would have softened an outer layer and made it easier to work. When Aranguren and her colleagues tried working some boxwood branches, they found that they couldn’t shape the rounded handles and blunt points without charring the wood first.

Modern hunter-gatherers use the same method today, but we’ve never found evidence of the technique being used so early. Some archaeologists think that Homo heidelbergensis, an ancestor of Neanderthals, may have used a similar method to shape spears in a 300,000-year-old site in Germany. The German tips come to much sharper points than the digging sticks at Poggetti Vecchi, but there’s no physical evidence for the use of flame.

That makes the Poggetti Vecchi digging sticks the earliest clear examples of wooden tools shaped with fire. They show that even early Neanderthals knew enough to choose the best wood for the tool—not just pick up whatever sticks happened to be lying around or easy to work with—and then utilize both fire and stone tools in order to produce a finished tool. It takes a lot of planning, specific knowledge, and painstaking, precise work to pull that off, which demonstrates the sophistication of Neanderthal tool-making abilities.

A look at prehistoric women’s lives

And the Italian find also adds a chapter to the story of how humanity adopted and tamed fire. Archaeologists still aren’t sure exactly when, or how, humans first learned to use and control fire and then to create it at their convenience.

“Most recent studies suppose during the Middle Pleistocene, a regular use of natural fire sources with perhaps the occasional development of fire-making technology,” said Arunguren. If by 171,000 years ago, Neanderthals were using fire in very precise, complex ways, that’s either an indication of how quickly our collective fire-handling skills advanced or a hint that fire use may be older than the first evidence we have for it so far.

The Poggetti Vecchi digging sticks may also be some of the earliest known tools used specifically by women. In most modern hunter-gatherer cultures, digging sticks are women’s tools.

“Digging sticks are mostly used by women and regarded as women’s personal property, in the same way that spears are regarded as men’s personal property,” wrote Aranguren and her colleagues. These artifacts may offer new insight into Neanderthal women’s lives and work. And they’re also an indication that a whole Neanderthal community, not just an all-male hunting party, may have spent time on the rich lakeside hunting grounds of Poggetti Vecchi.

PNAS, 2017. DOI: 10.1073/pnas.1716068115 (About DOIs).