Portugal’s Oldest Skull Adds to Puzzle of Human Evolution

Virtual reconstruction of the Aroeira 3 cranium as seen from the front (A), back (B), top (C), and side (D). Image Credit: Zilhão et al. in PNAS, 2017

When archaeologists were digging up the dirt floor at the Aroeira cave in central Portugal in 2014, they were already well on their way to understanding the lifestyle of hunter-gatherers who took shelter there during the Middle Pleistocene.

The researchers had found Acheulean handaxes—the most advanced technology of the day—that were used for cutting, scraping, and butchering. They also found burnt deer bones, suggesting that whoever camped out at this cave 400,000 years ago had the know-how to make fires—then a relatively new human achievement.

Then, at the end of the field season, the excavators unexpectedly struck paleoanthropological gold. They were using demolition hammers to break through the cave’s hard fragmented rock when they chipped a piece of bone.

“Immediately we knew we were dealing with a human fossil,” said University of Barcelona archaeologist João Zilhão, the director of the excavation. His team removed a block of the sediment surrounding the fossil, and preparators in Madrid spent two years carefully revealing a human cranium encased inside. Their findings are reported in the current issue of the Proceedings of the National Academy of Sciences.

It’s exceptionally rare to find human remains from this period. It’s even more rare to find them in a good archaeological context, among artifacts like tools and animal bones. So the discovery of this skull—the oldest ever found in Portugal—is exciting for some paleoanthropologists.

Below, you can see the researchers' discovery, removal, cleaning, and finally restoration of the ancient cranium.

Zilhão et al. in PNAS

The prehistoric skull from Aroeira shares some similarities with human fossils of the same era found in Spain, France, and Italy—including some fossils thought to be early Neanderthals, which were just starting to emerge in Europe, and some fossils that had been attributed to another species, Homo heidelbergensis. But the new specimen doesn’t fit neatly into a species category, and could help researchers argue for a diversity of human populations in Europe before the rise of modern humans.

Mental_floss spoke to a trio of experts in human evolution for their take on the current study, which they were not involved in. “This find adds more complexity to the European picture, as we are also seeing in Africa and Asia,” Chris Stringer, a paleoanthropologist at London’s Natural History Museum, says.

University College London paleoanthropologist Maria Martinón-Torres sees the skull as a potential ancestor to the Neanderthal. “I think this finding obliges us to abandon the idea that Neanderthal evolution is a single and lineal process,” she says.

She noted that there are several fossils from similar mid-Pleistocene sites, such as Sima de los Huesos in Atapuerca, Spain and Arago in France, that share some Neanderthal traits but have very different combinations of those traits.

“We see now that there is no linearity in the combination of these traits,” Martinón-Torres says. “This is probably due to the fragmentation and isolation of these populations due to the hard climatic conditions in Europe at that time.” She said that when climatic conditions are harsh, populations can get isolated and evolve their own particular distinctive features. Then, when conditions get better, these groups meet and recombine again. “So for a long period we will find a Neanderthal-like but highly variable population,” she says.

Bence Viola, a paleoanthropologist at the University of Toronto, notes that with the addition of the Aroeira skull we now have a few different humans fossils that look quite different from one another despite being from the same period. He says the new skull seems more primitive than the fossils found nearby at Sima de los Huesos, which, ancient DNA results have shown, represent early Neanderthals. “This cranium makes this scenario of having several different populations in Europe in the middle Pleistocene seem likely,” says Viola, who adds that he would be very interested to see what this specimen’s DNA looks like.

Stringer points out that the skull would be even more illuminating if it weren't missing some key parts, including the back of the cranium: “Unfortunately, this new fossil, interesting as it is, doesn’t have the most useful bits to put it into this puzzle."

Scientific Reports, Fernando Ramirez Rozzi
Stones, Bones, and Wrecks
Humans Might Have Practiced Brain Surgery on Cows 5000 Years Ago
Scientific Reports, Fernando Ramirez Rozzi
Scientific Reports, Fernando Ramirez Rozzi

In the 1970s, archaeologists discovered a site in France containing hundreds of cow skeletons dating back 5000 to 5400 years. The sheer number wasn't surprising—human agriculture in that part of the world was booming by 3000 BCE. What perplexed scientists was something uncovered there a few decades later: a cow skull bearing a thoughtfully drilled hole. Now, a team of researchers has released evidence that suggests the hole is an early example of animal brain surgery.

Fernando Ramírez Rozzi, a paleontologist with the French National Center for Scientific Research, and Alain Froment, an anthropologist at the Museum of Mankind in Paris, published their findings in the journal Nature Scientific Reports. After comparing the opening to the holes chiseled into the skulls of humans from the same era, they found the bones bore some striking similarities. They didn't show any signs of fracturing from blunt force trauma; rather, the hole in the cow skull, like those in the human skulls, seemed to have been carved out carefully using a tool made for exactly that purpose. That suggests that the hole is evidence of the earliest known veterinary surgery performed by humans.

Trepanation, or the practice of boring holes into human skulls, is one of the oldest forms of surgery. Experts are still unsure why ancient humans did this, but the level of care that went into the procedures suggests that the surgery was likely used to treat sick patients while they were still alive. Why a person would perform this same surgery on a cow, however, is harder to explain.

The authors present a few theories, the first being that these ancient brain surgeons were treating a sick cow the same way they might treat a sick human. If a cow was suffering from a neural disease like epilepsy, perhaps they though that cutting a hole in its head would relieve whatever was agitating the brain. The cow would have needed to be pretty special to warrant such an effort when there were hundreds of healthy cows living on the same plot of land, as evidenced by the skeletons it was found with.

Another possible explanation was that whoever operated on the cow did so as practice to prepare them for drilling into the heads of live humans one day. "Cranial surgery requires great manual dexterity and a complete knowledge of the anatomy of the brain and vessel distribution," the authors write in the study. "It is possible that the mastery of techniques in cranial surgery shown in the Mesolithic and Neolithic periods was acquired through experimentation on animals."

Either way, the bovine patient didn't live to see the results of the procedure: The bone around the hole hadn't healed at all, which suggests the cow either died during surgery or wasn't alive to begin with.

Stefan Sauer, AFP/Getty Images
Stones, Bones, and Wrecks
13-Year-Old Amateur Archaeologist Discovers the Buried Treasure of a Danish King
Stefan Sauer, AFP/Getty Images
Stefan Sauer, AFP/Getty Images

In January, amateur archaeologist René Schön and his 13-year-old student Luca Malaschnitschenko were scouring a field on an island in the Baltic Sea when something small and silver triggered their metal detector. What they initially thought was aluminum trash turned out to be a coin from a 10th-century treasure hoard that once belonged to a Danish king, AP reports.

Schön and Malaschnitschenko discovered the site on the eastern German island of Ruegen, but it wasn't until mid-April that state archaeologists uncovered the hoard in its entirety. Both of the amateur archaeologists were invited back to take part in the final dig, which spanned 4300 square feet.

The treasure trove includes pearls, jewelry, a Thor's hammer, and about 100 silver coins, with the oldest dating back to 714 CE and the most recent to 983 CE. Experts believe the collection once belonged to the Viking-born Danish king Harald "Harry" Bluetooth, who abandoned his Norse faith and brought Christianity to Denmark.

Pile of silver coins.
Stefan Sauer, AFP/Getty Images

Threatened by a rebellion led by his son, the king fled Denmark in the late 980s—around the same time the silver hoard was buried—and took refuge in Pomerania, on the southern coast of the Baltic Sea. He died there in 987.

Harry Bluetooth derived his nickname from his bluish dead tooth. Today his legacy lives on in the Swedish Bluetooth technology that bears his name. The symbol for the tech also uses the runic characters for his initials: HB.

According to the archaeologists who worked there, the dig site represents the largest trove of Bluetooth coins ever discovered in the southern Baltic region.

[h/t AP]


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