Researchers in Australia, New Zealand and the U.S. say they've potentially identified the "oldest known tsunami victim in the world."
It's not from a new discovery, but from researching the sediment in the area where an ancient skull was discovered in 1929.
Geologist Paul Hossfeld discovered the "Aitape Skull" in northern Papua New Guinea that year and believed it to be from a species called Homo erectus, an early relative of humans that lived more than 1 million years ago. But it was later "radiocarbon dated" to being only about 6,000 years old.
Researchers James Goff, Mark Golitko, Ethan Cochrane, Darren Curnoe, Shaun Williams and John Terrell said they "conclude that the skull was laid down in a tsunami deposit and as such may represent the oldest known tsunami victim in the world. These findings raise the question of whether other coastal archaeological sites with human skeletal remains would benefit from a re-assessment of their geological context."
The study was published in the journal PLoS ONE on Wednesday.
The researchers traveled in 2014 to the same area of northern Papua New Guinea where Hossfeld discovered the skull 85 years earlier — "along the foothills of the Torricelli Mountains some 12 km inland from Sissano Lagoon."
It was also the site of heavy damage from a major tsunami in 1998 that killed more than 2,000 people. "[T]he unique introduction of marine sediments that encased the Aitape Skull is consistent with conditions reported following the 1998 PNG tsunami," the researchers write.
It was evidence that the skull was from an individual killed in a tsunami about 6,000 years ago.
The New York Times offered this explanation:
"Because they had previously analyzed geochemical signals from sediment on the island following the 1998 tsunami, the team knew which clues to look for, like grain size and composition.
"They found that the sediment collected from the skull site contained fossilized deep sea diatoms. These microscopic organisms were a telltale sign that ocean water had drowned the area at some point.
"The researchers also found geochemical signals that matched the signatures they collected in 1998, offering additional evidence that a tsunami had struck around 6,000 years ago."
The researchers say the finding shows that "tsunamis may have contributed to a much more dynamic world of community and individual mobility" among those alive during the period, in turn leading to "wider-ranging social ties, and ... the spread of materials and new ideas and practices" in the southwest Pacific during the period several thousand years ago.