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Aerial photo of site Mt05, a circular enclosure (140 meter diameter) located on a hilltop.
Aerial photo of site Mt05, a circular enclosure (140 meter diameter) located on a hilltop.
José Iriarte

Part of the Amazon Thought to Be Uninhabited May Have Been Home to 1 Million People

Aerial photo of site Mt05, a circular enclosure (140 meter diameter) located on a hilltop.
Aerial photo of site Mt05, a circular enclosure (140 meter diameter) located on a hilltop.
José Iriarte

Depictions of the pre-Columbian Amazon basin as dense, inhospitable jungle with just a handful of indigenous communities scattered along the river may need to be updated. According to research published in Nature Communications, there were millions more people living in the rainforest prior to Spanish colonization than previously believed.

The Amazon is the largest rainforest on Earth, which poses a challenge to archaeologists exploring the history of the people who lived there. It's long been assumed that native Amazonians chose to avoid the heart of the forest and instead lived as nomads, never straying far from the major rivers. Some old estimates placed the population of the entire basin between 1.5 and 2 million people.

Thanks to satellites, researchers can now identify traces of long-gone settlements in the less-explored regions of Brazil without having to set foot in the jungle. A team of archaeologists from the University of Exeter used satellite imaging to find geoglyphs—large shapes dug into the ground, possibly for ceremonial purposes—in part of the Brazilian state of Mato Grosso that was thought to be uninhabited.

Geoglyphs and mounded ring villages.
Geoglyphs and mounded ring villages.
Nature Communications, Jonas Gregorio de Souza et al.

After pinpointing the locations of these earthworks, archaeologists visited this section of the southern rim of the Amazon to see some of them in person. At each of the 24 sites they set out to confirm, they found a real-life geoglyph on the ground. At one location, they uncovered charcoal and pottery dating back to 1410 CE. In all, they documented 81 new sites with geoglyphs.

The earthworks would have been carved into the dirt during a seasonal drought, allowing the architects to clear a swath of rainforest. Fortified villages were built in or close to the glyphs, with a network of roads connecting them to each other. The researchers created a computer model that estimated that a 154,000-square-mile patch of land could be home to the remains of 1300 geoglyphs and villages, only two-thirds of which have been discovered. In the late pre-Columbian period, the area, comprising just 7 percent of the Amazon basin, may have sustained a population of 500,000 to 1 million people, according to the researchers' models.

Aerial photo of site ZMt04, which contains the two largest enclosures that were identified.
Aerial photo of site ZMt04, which contains the two largest enclosures that were identified.
José Iriarte

Disease and genocide brought on by the European invasion destroyed most of those settlements, and they were later reclaimed by the rainforest. But evidence of their existence suggests that deforestation and development of the Amazon isn't a new phenomenon.

"Our research shows we need to re-evaluate the history of the Amazon. It certainly wasn't an area populated only near the banks of large rivers, and the people who lived there did change the landscape," researcher José Iriarte said in a statement. "Studies such as ours mean we are gradually piecing together more and more information about the history of the largest rainforest on the planet."

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Aerial photo of site Mt05, a circular enclosure (140 meter diameter) located on a hilltop.
Scientific Reports, Fernando Ramirez Rozzi
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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.

nextArticle.image_alt|e
Aerial photo of site Mt05, a circular enclosure (140 meter diameter) located on a hilltop.
Stefan Sauer, AFP/Getty Images
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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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