Stockholm University

8,000-Year-Old Smashed Skulls on Spikes Found in Sweden, And Nobody Knows Why

Posted by

1


This is totally weird.

Archaeologists in Sweden have unearthed human remains of a type never before found in Scandinavia.

The enigmatic Mesolithic bones show evidence of blunt force trauma to several skulls – and evidence that heads were displayed on stakes. But none of it is straightforward, which presents a number of really intriguing mysteries.

For one, the bones show evidence of healing, which means the blows to the head weren’t necessarily what killed these people.

There are also signs that the bodies were buried prior to their heads being exhumed, and the skulls being mounted on spikes.

If you’re wondering what the heck happened, you’re in good company: the archaeologists from Stockholm University in Sweden are also baffled.

The bones were found some years ago, during excavations between 2009 and 2011 at a peat bog site called Kanaljorden near the Motala ström river system in central Sweden.

They were unlike anything found before, and the pattern in which they were laid out, in the lime sediment at the bottom of what was once a lake, suggested a ceremonial purpose.

Now a team of researchers has completed an analysis of the assemblage, including skulls or skull parts from at least 10 individuals.

When they were excavated, two of the skulls were found to be mounted on stakes, driven straight through the bottom of the skull to the top.

In the lake, there had once been a compacted stone platform, possibly where rituals were conducted, with the remains of two settlements on the banks nearby showing a hunter-gatherer culture had been active in the area.

Radiocarbon dating indicated the remains are from the Mesolithic period, sometime between 5500 and 6000 BCE – around 8,000 years ago.

Animal bones from at least seven different species, including boar, bear and badger, were arranged around the skulls. Marks on these bones suggested the animals were butchered after death, but not for eating, since there was no evidence of fire on the bones.

The human skulls is where things get peculiar. Nine of the 10 distinct individuals were adults, and the researchers identified two of them as female, and four as male. Another two heads belonged to people aged between 20 and 35, and one was over the age of 50.

The remaining individual, known from a complete skeleton, was either a foetus or a newborn, aged between 36 and 40 weeks, indicating that the baby had died very shortly before or after being born.

skulltraumamarkingsThe male trauma injuries are shown in black, the female in grey. (Gummeson et al./Antiquity)

Of the adult skulls, seven had shallow blunt force trauma injuries. Both females had been hit on the back of the head multiple times, while the males were hit once on the top of the head.

There was also evidence that some of these injuries had healed – so they may not have died from a blow to the head.

It’s impossible to identify the weapon that made the wounds, but they do seem to have occurred by violence rather than accidents. They are too similar to each other, and above what’s known as the hat-brim line, making them unusual for accidental injuries.

“These are not people who have been recently smashed in the head and then put on display,” one of the team, Fredrik Hallgren told National Geographic. “More than half of them had this healed trauma to the head.”

The most likely explanation is inter-group violence such as raiding and warfare, the researchers said. This would explain the healed traumas, and the different injuries for men and women could be because they played different roles in combat.

There’s also evidence to suggest the bodies had been buried, before the heads were dug out and placed in the lake. Most of the skulls were missing their jawbones, with no markings to suggest that they had been forcibly removed.

Instead, this suggests the bodies were at least partially decomposed – although the presence of preserved brain matter in one of the skulls also suggests they could have been deposited not long after death.

This could also have been achieved by exposing them to the elements, but the lack of tooth marks from the wild animals that would have inevitably been attracted to the rotting corpses suggests they would have had to have been protected somehow.

Then there are the stakes. The team found over 400 wooden stakes, either intact or fragmented. Some could have been used as a partition or fence; others, as indicated by skulls with stakes inserted through the hole in the base of the skull for the spinal cord, to mount human and animal heads, the researchers said.

Research to figure out why the skulls were in the lake is ongoing, as well as searching nearby bogs in the hopes of finding similar sites.

But one thing, the researchers said, is clear: the skulls had to have been placed in the lake on purpose.

“The deposition can be described as being carefully planned and executed, from the construction of the underwater stone packing to the spatially separated depositions of curated human and animal remains,” they wrote in their paper.

“The fact that the majority of the individuals show healed injuries seems to be more than a coincidence and implies that they were specifically chosen for inclusion in the deposition.”

Let’s hope that future discoveries at the site will bring some clarity to this bizarre story.

Soure: Antiquity.

Like Father, Like Son.

Posted by

0


A 10-year-old boy spends his summer vacation helping his chemist dad solve the structure of complicated materials.

Chemist Sven Hovmöller of Stockholm University had been trying for nearly a decade to determine the structures of materials known as quasicrystals and their nearly identical approximants. Thought to be physically impossible until some 30 years ago, quasicrystals are aperiodic structures—meaning they don’t display the rigidly repeating patterns characteristic of crystals like sodium chloride, for example. Since their discovery in the lab, physicists had been working tirelessly to better understand the structure of quasicrystals. But because the existence of such materials was doubted for so long, computer programs currently used to interpret imaging data aren’t equipped to analyze the aperiodic structures.

Hovmöller has worked on and off in the field of quasicrystals for more than 25 years, focusing primarily on the aluminum-cobalt-nickel (Al-Co-Ni) system. Like other quasicrystal researchers, he studied not the elusive materials themselves but their approximants, which differ in atom placement by only 1 or 2 percent and have more tractable patterns of atomic arrangement. Hovmöller’s interest in quasicrystals was piqued when he saw a conference poster displaying an electron diffraction pattern of one of the Al-Co-Ni approximants. The image was “so beautiful, so clear, [that] it should be possible to solve it,” recalls Hovmöller, who immediately invited Markus Döblinger, the student who made the poster, to do a postdoc in his lab.

But after months of further electron microscopy studies, the duo couldn’t seem to solve the structure. “Not only him and me, but other people also involved, tried so hard, but we didn’t get anywhere,” Hovmöller recalls. “It was extremely annoying.”

The image was so beautiful, so clear, that it should be possible to solve it.
—Sven Hovmöller, Stockholm University

Döblinger eventually moved on to the University of Munich, but Hovmöller couldn’t let the idea go. “Every year, once or twice, I [tried] to solve these things, and I just couldn’t.” Then, last summer, he had a seemingly off-the-wall idea. He’d enlist the aid of his 10-year-old son, Linus. “I thought, He’s a smart guy; maybe he could help me,” Hovmöller says.

The father-and-son team sat at the kitchen table for 2 days, poring over the dozens of electron microscopy images Döblinger had generated, as well as some electron diffraction data, which provides more precise information on the materials’ atomic positions. Hovmöller would explain to Linus what he was thinking about how the images all fit together, and when Linus didn’t understand something, he’d interrupt his father to ask. This made Hovmöller realize that he was rushing to conclusions. When he slowed down to clear up Linus’s confusion, he’d get new ideas. “In 2 days, we solved four new structures.”

They published their findings in a special issue of Philosophical Transactions of the Royal Society A honoring the 85th birthday of Alan Mackay, who had predicted the existence of quasicrystals before they were identified in 1982. Linus was listed as a coauthor on the paper (370:2949-59, 2012).

“A kid [who] is clever and good at spatial things might well come up with a solution to a problem like that,” says surface physicist Renee Diehl of Penn State University. “I think there’s probably a lot of potential in 10-year-old kids that we’re not tapping.”

And in fact, Linus isn’t as unlikely a character as one might expect in the field of quasicrystals. “There have been a lot of highly creative and unusual people associated with the field,” says Carnegie Mellon University theoretical physicist Mike Widom. Amateur mathematician Robert Ammann, for example, made several significant contributions to quasicrystal theory before the crystals were even proven to exist. Others have pointed to the links between quasicrystals and art, such as aperiodic tilings and mosaics found in Persia. There’s even a company, called Zometool, that manufactures toys used to model quasicrystalline shapes, Widom notes. “The field is quite rich … [in] unusual personalities,” he says. “This boy is in the tradition of the field attracting some nontraditional scientists.”

But all the structures of the Al-Co-Ni quasicrystal and its approximants aren’t exactly solved. “What Sven Hovmöller did is quite nice,” says Walter Steurer of the Laboratory of Crystallography at ETH Zurich, but his methods are qualitative. Thus, Hovmöller and Linus merely mapped out some of the repeating motifs in four of the approximant structures, but “did not publish any atomic coordinates.” The precise locations of some of the crystals’ atoms have yet to be pinpointed.

“A lot of the interesting controversy in the field of quasicrystals has to do with fairly fine details,” which are critically important to understanding the materials’ true structures, Widom says. “You can know where 90 percent of the atoms are, but still not really know the structure because a minority of the atoms are doing interesting and crucial things. . . . What [Hovmöller and Linus] give us is a good starting point for future structure refinement.”

But if someone eventually solves the true structure of the Al-Co-Ni quasicrystal or its approximants, it won’t be Linus. “He’s refused” to work on the remaining structures, Hovmöller says with a laugh. “He’s still a little bit tired” from the last bout of structure solving.

http://www.sciencedaily.com