The pit contained three sets of human bones, as well as animal skeletons and broken pottery. Workers at a private company found the pit in 2013, during the construction of a highway near the town of Osijek in eastern Croatia.
The skulls were intact. Two of them were also misshapen.
“A friend, the owner of this company, he called and told me, ‘Oh Mario, I think we have an alien here,’” recalled Mario Novak, an archaeologist at the Institute for Anthropological Research in Croatia. “Of course, it was a joke.”
Rather, the misshapen skulls — one had a flattened top, the other resembled an elongated egg — bore signs of artificial cranial deformation.
Practiced for some 5,500 years by cultures around the world, artificial cranial deformation involves binding the growing heads of infants and children with bandages, planks, boards or bricks. As the skull grows under constant pressure, it becomes misshapen, resulting in oblong heads and other unusual shapes. Anthropologists have documented this practice on every inhabited continent, but it isn’t common. Today it continues in only a few remote tribes.
The skulls unearthed near Osijek were the first with artificial cranial deformation found in Croatia.
To find out who these people were, Dr. Novak and his colleagues examined the bones, scanned and reconstructed the skulls and analyzed their DNA. Their findings, published Wednesday in the journal PLoS One, suggest that between the fifth and sixth centuries A.D., during the Migration Period, people of starkly different cultural backgrounds may have interacted more than previously thought. The study also provides the earliest genetic evidence of the presence of people from East Asia in Europe.
The analysis revealed that the skulls belonged to three malnourished males, between the ages of 14 and 16, who had lived between 415 and 560 A.D. There were no signs of violent death.
DNA testing revealed the flat-topped skull hailed from somewhere in the Middle East, northern Africa or southeastern Europe. The egg-shaped skull belonged to someone from East Asia. The unaltered skull likely came from a person of west Eurasian ancestry. Their genes were relatively unmixed, suggesting they had moved from these places or their parents had.
While there was not enough information to assign the remains to any particular population, the study said “it is possible that these individuals were Huns, Ostrogoths or Gepids.”
“It’s sort of strange, or interesting, that they were found in the same pit, but genetically they were from different parts of the world,” said Ron Pinhasi, an evolutionary anthropologist at the University of Vienna, who conducted the genetic analyses.
How did three teenagers, two of them with misshapen skulls, from thousands of miles apart in a time where travel wasn’t easy, wind up in a pit next to a highway in the middle of Croatia?
For the researchers, it was a difficult mystery, packed with surprises. For instance, artificial cranial deformation is more common among females; the scientists couldn’t explain why the skulls belonged to males.
They were also puzzled that the remains were “haphazardly positioned” in the pit, but were found alongside significant items, such as pottery and animal bones, as if they had been deliberately buried. Typical cemeteries of the time contained people of similar heritage, near their settlements. That wasn’t the case here.
And while the fifth and sixth centuries were times of great chaos, with everyone fighting until Rome fell, the researchers reasoned that these uninjured, unrelated bodies probably weren’t casualties of war, dumped in a mass grave.
Dr. Novak speculated that they may have died as part of a ritual sacrifice, because the contents of the pit were similar to those found in other cases of sacrifice from the same period.
Artificial cranial deformation has been studied for two centuries, but whether it signals high status, beauty, fashion or tribal group affiliation is still a mystery. The team investigating the Croatia burial site suspects that the misshapen heads of two of its occupants helped differentiate them from other immigrants commingling at the first rest stop on a long migration.
“This was an entrance area to Europe,” Dr. Novak said. “All great migrations from the east entering Europe came through this part. We think they just happened to be there at the same time.
“We don’t know the reasons why,” he said, “but if you ask me, I don’t think we’ll ever be able to answer those questions.”