3,000-Year-Old Murder Mystery Solved: Shark Attack

3,000-Year-Old Murder Mystery Solved: Shark Attack
Original excavation photograph of Tsukumo No. 24. The man died after being attacked by a shark or sharks, according to a new analysis of his injuries. (Photo: Laboratory of Physical Anthropology, Kyoto University)

A large shark, possibly a great white or a tiger, fatally attacked a young man. The man’s wounds were extensive, including the loss of a leg, a hand, and both feet. Thanks to those at the time who recovered his body and the way in which they buried him, his bones survived 3,000 years to tell us a horrific story of the last moments of his life.

Today he’s known as Tsukumo No. 24, one of over 170 skeletons excavated from a site in Japan. We now know more about this poor man and the trauma he endured because of a paper published last week in The Journal of Archaeological Science: Reports.

The site itself — a series of graves known as shell-mounds, a term describing the funerary practices of the Jōmon people in early Japan — was accidentally discovered in the 1860s during a construction project. “The calcium carbonate in the shells helps to protect the skeletons from the relatively acidic soil in Japan,” said lead author J. Alyssa White, DPhil candidate in archaeology at the University of Oxford.

This man was excavated over a hundred years later and has been examined numerous times since. But the massive gouges, pits, and slashes on his bones weren’t interpreted until White and her international team really took a hard look at those marks.

Image: J. Alyssa White/Laboratory of Physical Anthropology, Kyoto University Image: J. Alyssa White/Laboratory of Physical Anthropology, Kyoto University

That he died violently was obvious. Co-author Masato Nakatsukasa, a professor at Kyoto University, said it’s highly likely that all former researchers noticed the profuse number of marks on the bones. Ancient tools of that time, however, wouldn’t have matched what remained on the skeleton, ruling out human-on-human violence. Outside of black bears and wolves, Nakatsukasa wrote, Japan isn’t home to large carnivorous predators, but archaeologists — including this team — have nonetheless pondered whether “the Jōmon people might have been the target of predation.”

Because the researchers couldn’t find animal marks that matched those on this skeleton, and knowing that the Jōmon people relied on marine resources, they turned to ocean predators. That, according to Rick Schulting, professor of scientific and prehistoric archaeology at the University of Oxford, is what led them to George Burgess, director emeritus of the Florida Program for Shark Research and curator emeritus of the International Shark Attack File. And Burgess confirmed it: This was the work of at least one shark, if not more. This is now the oldest shark attack on record by 2,000 years.

Image: J. Alyssa White/Laboratory of Physical Anthropology, Kyoto University Image: J. Alyssa White/Laboratory of Physical Anthropology, Kyoto University

A brutal 790 traumatic lesions from shark teeth in the form of deep cuts, fractured ribs, bite marks, and puncture wounds remain on this skeleton. To better understand the lesions and the type of trauma they inflicted, the team used a variety of technologies, including 3D imaging, CT scans, and, remarkably, GIS (Geographic Information System), software that is often used to help visualise data related to landscapes and cityscapes.

“Archaeologists have a long history of working with technology,” explained John Pouncett, research fellow in Spatial Archaeology at the University of Oxford. “They also have a habit of using technology to do things it wasn’t necessarily intended to.”

What the team created is a powerful research tool that enables them (and anyone in the field of forensics or archaeology) to recreate trauma to bones on a 3D image of a human body. In this case, White painstakingly added the hundreds of shark tooth injuries on specific parts of each bone, enabling them to see, in graphic detail, the injuries this man sustained. This, White said, “was incredibly helpful to be able to see all of his injuries in 3D when we were beginning to piece together the pattern of attack.”

The upgrade is infinitely clear when one sees currently available tools (a mere 2D image with ‘x’s’ to generally mark where the trauma occurred) and compared to the customisable, searchable, and interactive 3D version the team has created. It’s a vast improvement, on par with moving from word processing to a computer.

Screenshot of the Tsukumo 24 BodyMap 3D web app showing the distribution of wounds. The app was developed by John Pouncett, Rick J. Schulting, and J. Alyssa White using a modified version of the BodyParts3D model. (Screenshot: J. Alyssa White) Screenshot of the Tsukumo 24 BodyMap 3D web app showing the distribution of wounds. The app was developed by John Pouncett, Rick J. Schulting, and J. Alyssa White using a modified version of the BodyParts3D model. (Screenshot: J. Alyssa White)

“To the best of our knowledge, this is the first time that GIS has been used to map the human body in 3D,” Poucett said. “The distribution of the trauma on the skeleton presented challenges for traditional 2D methods of recording — not least, how to represent the damage to the inside of the rib cage. Working with a 3D model of the skeleton allowed us to document all of the trauma. It also allowed us to understand the impact that the skeletal trauma would have had on other parts of the human body. The visualisation of the blood vessels that would have been severed by the trauma on the lower left leg highlights this impact in a visceral way.”

Severed blood vessels or an amputated leg, according to Burgess, may have contributed to a mercifully swift death.

“When a human being dies as a result of a shark bite, it’s usually because they exsanguinate, they lose blood. All it takes is one tooth hitting an artery to kill a person,” Burgess explained. And yet, he noted, “For all of the bite marks on the skeleton, it’s a pretty intact skeleton.”

So while we may recoil in horror at what remains of individual No. 24 and what those remains imply, Burgess suggested he may have died soon after the initial bite from loss of blood. The rest of his injuries, therefore, might have occurred after death, when other sharks may have scavenged his corpse.

But that’s only one possible scenario. The authors point out that the loss of No. 24’s hand and the multiple wounds along the arms may represent degloving, the term for when a shark strips the hand of all flesh when a person tries to ward off the attack. If so, these would be defensive wounds, suffered while No. 24 was very much alive and aware of what was happening.

This type of brutal attack speaks to a primal fear among most of us, and it is why, even 3,000 years later, we are equally fascinated and horrified. But the authors are quick to point out that shark attacks are relatively rare; despite terrifying examples like this one, sharks generally aren’t a danger to humans. Burgess, who has spent most of his career studying sharks and shark attacks, says that the average number of shark attacks per year worldwide is about 75. Of those 75 attacks, only six are fatal. He encourages people to consider the potential billions of hours globally people spend in the water in comparison to those numbers, saying that on the list of causes of human death, “shark attack would be down at the bottom of the page, with a little asterisk under the ‘Other’ category.”

“On the other hand,” Schulting said, “it has been estimated that humans are killing 100 million sharks annually… This is unsustainable and will lead to the extinction of a number of shark species, which would be very unfortunate to say the least. We’d like people to reflect on this, and to make space to allow co-existence with these incredible animals.”

As for No. 24, it is particularly poignant that his body was retrieved from the sea at all. We don’t know the circumstances that caused him to be in the ocean then, nor the circumstances around the attack. But we do know that someone cared enough about this man to bury his body, even a severed leg, in the customary manner of the time.

As White described, “We have no way of knowing whether or not the attack was witnessed, and we can’t say for certain that he was recovered in deeper water, although this is quite likely. There is a chance that his body could have drifted ashore, but, given the recovery of highly impacted areas of the body (i.e. the detached left leg), at the least it is obvious that great care was taken to recover as much of him as possible.”

Jeanne Timmons (@mostlymammoths) is a freelance writer based in New Hampshire who blogs about paleontology and archaeology at mostlymammoths.wordpress.com.