Cold-case files: Archaeologists discover 3,000-year-old victim of shark attack

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Original excavation photograph of Tsukumo No. 24, a young adult male with evidence of severe trauma consistent with an attack by a white or tiger shark.
Enlarge / Original excavation photograph of Tsukumo No. 24, a young adult male with evidence of severe trauma consistent with an attack by a white or tiger shark.
Kyoto University

Marine biologists have spent decades counteracting the popular misconception that sharks are aggressive predators that target humans, an idea that became particularly prevalent in the wake of the blockbuster Jaws franchise. But fatal attacks nonetheless do happen—and they happened even in prehistoric times. While examining the skeletal remains of a prehistoric hunter-gatherer cemetery in Japan dating back some 3,000 years, University of Oxford archaeologists found distinctive evidence that one such skeleton had been the victim of a fatal shark attack. They described their findings in a new paper published in the Journal of Archaeological Science: Reports. It’s the oldest known victim of a shark attack yet—like a prehistoric cold-case film.

The Tsukumo burial site in Japan’s Okayama Prefecture was discovered by construction workers in the 1860s and first excavated in 1915. More than 170 human skeletons were unearthed and housed at Kyoto University. The site dates to the Late-Final Jōmon period of the Japanese archipelago. Co-authors J. Alyssa White and Rick Schulting, both from Oxford, made their discovery while examining the remains for evidence of violent trauma, part of a larger study on violence in prehistoric Japan. Remains categorized as Tsukumo No. 24 showed marks of severe trauma that proved especially puzzling.

“We were initially flummoxed by what could have caused at least 790 deep, serrated injuries to this man,” said White and Schulting. “There were so many injuries and yet he was buried in the community burial ground, the Tsukumo Shell-mound cemetery site. The injuries were mainly confined to the arms, legs, and front of the chest and abdomen. Through a process of elimination, we ruled out human conflict and more commonly-reported animal predators or scavengers.”

The team quickly realized the injuries were similar to those left by shark attacks on both modern and archaeological remains. According to the authors, sharks tend to attack (unprovoked) in three different ways. “Hit and runs” usually are single bites and occur in the surf zone; they are rarely fatal. In “bump and bite” attacks, a shark will circle its prey and bump them before attacking; and there is no advance warning when sharks execute a “sneak attack.” Those latter two attack types are far more likely to be fatal.

Injuries from shark attacks can leave very distinctive signs of trauma on the bones, typically caused by cutting, crushing, and tearing by those sharp, sharp teeth. Legs are particularly favored human targets, as is the thorax. Stripped flesh from arms and hands (“degloving”) often occurs because the victims try to defend themselves from the attack. Other bone-related evidence of a shark attack includes punctures, gouges, and fractures from the sheer force exerted by powerful jaws, and overlapping serrated (for white, bull, and tiger sharks) striations caused by the teeth scraping across the bone.

These were the types of trauma the authors found on Tsukumo No. 24 during their examination, which involved creating 3D distribution maps of the injuries and comparing them to the photographs and CT scans of the skeleton. No. 24 was a young adult male with evidence of nearly 800 separate perimortem lesions and no signs of any initial stages of healing, meaning he would have died shortly after receiving the lesions.

Most of the injuries are concentrated on the pelvis, left leg, arms, and shoulders. Both the right leg and left hand are missing, and trauma to the remaining adjacent arm bones is consistent with the hand being torn off—most likely a defensive wound. “It is probable that the missing right leg was entirely separated from the body by the shark and either consumed or not recovered,” the authors wrote.

The left tibia had the highest number of deep bites, and nearly all the ribs were fractured, as was the pelvis. The authors suggest the chest cavity and abdomen may have been eviscerated, and they believe the young man was alive when he was attacked. Cause of death was probably severe loss of blood (exsanguination) given the likely severance of the femoral arteries and extreme shock. He probably died between 1370 to 1010 BC.

“Given the injuries, he was clearly the victim of a shark attack,” said White and Schulting. “The man may well have been fishing with companions at the time, since he was recovered quickly. And, based on the character and distribution of the tooth marks, the most likely species responsible was either a tiger or white shark.”

The authors base that conclusion on the fact that the remains of both tiger and white sharks have been found at sites from the Jōmon period. “The Neolithic people of Jomon Japan exploited a range of marine resources,” said co-author Mark Hudson of the Max Planck Institute for the Science of Human History. “It’s not clear if Tsukumo 24 was deliberately targeting sharks or if the shark was attracted by blood or bait from other fish. Either way, this find not only provides a new perspective on ancient Japan, but is also a rare example of archaeologists being able to reconstruct a dramatic episode in the life of a prehistoric community.”

DOI: Journal of Archaeological Science: Reports, 2021. 10.1016/j.jasrep.2021.103065  (About DOIs).

https://arstechnica.com/?p=1776215