A boomerang carved from a mammoth tusk reveals complex symbolic thinking 42,000 years ago.

In the summer of 1985, the extraordinary happened. A team of Polish researchers began excavating Obłazowa Cave, located in the Western Carpathian Mountains, the only known Early Upper Paleolithic archaeological site in the Podhale Basin (Poland). Shortly after the excavation began, artifacts began to emerge from the earth. Among the finds was what appeared to be a 72-centimeter-long boomerang made from a mammoth tusk. Initial dating suggested it was 24,000 years old. However, a new analysis has shown that this complex artifact could be much older and is actually 42,000 years old.

The new dating, published Wednesday in the journal PLOS ONE , is by, among others, an Italian scientist, Sahra Talamo of the University of Bologna, a radiocarbon expert. For Talamo, the boomerang's initial chronology didn't add up and she suspected something had to be wrong. "I wanted to accurately establish the age of this unique object," she explained to EL PAÍS via video call. Evidence of the oldest boomerang known so far dates back 20,000 years and is from Australia, where they are most commonly found. "Finding one that old in Poland is very unusual, so it was crucial to know when it was made," she added.

It wasn't a simple task. In fact, the boomerang itself wasn't analyzed; rather, its age was inferred based on objects and bones found around it. Talamo explains the strategy: “When I first saw the object, I knew it shouldn't be destroyed again to obtain another sample. It would have been like damaging a Van Gogh or the Mona Lisa.” The scientist already knew that the artifact was also contaminated with the glue used for its restoration, so, just as had happened the first time, the results would have been unreliable. “So we opted for a different strategy: dating the animal bones surrounding the boomerang in the same layer of sediment in which it was found, in addition to reanalyzing a human phalanx that was found there, using noninvasive methods and new treatments that have advanced significantly in recent years,” she notes.

The mitochondrial DNA extracted from that phalanx was what helped determine that the object belonged to a Homo sapiens . This new certainty has helped reinforce the idea that modern humans in Central Europe already had complex symbolic and technological thinking more than 40,000 years ago. “We don't know exactly what they used the boomerang for, but some experts suggest ritual use , considering it was surrounded by large stones, uncommon at the site, and decorative objects, which is strange,” Talamo points out.

It could also have been a weapon. The artifact's midsection shows obvious wear, suggesting direct manual manipulation. The researchers' best bet is to interpret the object not only as a functional tool, but also as an artifact laden with meaning. However, the boomerang doesn't return. "Technically, we should call it a 'thrown weapon,' but in the original study ( published in Nature in 1987 ) they already considered it a boomerang, based on the criteria of its shape," the scientist says. Beyond this, "the most fascinating part of all," for Talamo, is the fact that the object "speaks of the sophisticated behavior" of its makers because the ivory was carved with a skill practically unheard of for its time.

An evolving method

“I would like to make one last comment,” Talamo says near the end of the interview. She adds: “I would like to emphasize that radiocarbon dating is not a static method; it is constantly evolving.” The expert is not referring to the technique itself, but rather to the methods used to minimize damage to valuable objects. Radiocarbon dating works like an invisible clock that measures time in any organic matter, from a piece of wood to a bone or a seed. All living beings accumulate carbon-14 (C-14), a radioactive isotope that begins to decay as soon as they die. By measuring how much C-14 remains in the material, scientists can cross-reference data and calculate its age, sometimes with an accuracy of just decades.

But to obtain an estimated date , a physical sample must be extracted from the original material, which entails the partial destruction of the object under study. However, "today, instead of using grams of a sample, milligrams are enough. Let's put it this way: if before, an entire finger was needed to date a specimen, now a fingernail is enough," the researcher explains.

It's crucial to preserve materials like the boomerang unaltered because, in the future, more precise technologies that don't involve altering the original objects could be developed. "This will allow us to better answer key questions about our evolution: When did we get here? When did we start creating objects like this? And why?" the scientist concludes.