Researchers Discover 80-Million-Year-Old Bite Marks on Canadian Fossil
Two potential bite marks discovered on an 80-million-year-old cephalopod fossil have revealed new clues about Cretaceous marine food webs in Manitoba, according to a report by ici.radio-canada.ca.
Researchers at the Canadian Fossil Discovery Centre (CFDC) in Morden examined museum drawers to unearth the specimen, which measures up to one meter long. While sorting through the facility’s collections, researchers Melina Jobbins and Kirstin Brink identified two distinct impact traces on the ancient marine mollusk.
Unearthing Museum Drawers in Morden
The fossil itself is not a recent excavation. Elizabeth Nicholls and her team originally discovered the specimen in 1980, according to Melina Jobbins, a paleontologist and research associate at the CFDC. Decades later, Jobbins spotted the impact marks while reviewing the center’s holdings, which mostly consist of vertebrates, small marine organisms, and a few birds.
Weighing the Evidence of Prehistoric Scars
Detailed examination of the fossil isolated two probable predation scars. Researchers expressed 90 percent certainty that the first mark stems from a bite, matching either a mosasaur tooth or a fish tooth. The second imprint, located toward the rear of the cephalopod, remains more mysterious, though investigators have formulated several hypotheses pointing toward a similar attack.
Mosasaur or Giant Fish in the Western Interior Seaway
Kirstin Brink, a professor in the Department of Earth Sciences at the University of Manitoba and assistant curator of vertebrates at the Morden center, took part in the study alongside Jobbins. She noted that while the attack is clear, the exact identity of the predator remains difficult to pin down.
“We are almost certain we’ve narrowed the possibilities down to a mosasaur or a very large fish,” Brink said.
Eighty million years ago, the region between Morden and Miami lay completely submerged beneath the Western Interior Seaway. That vast body of water covered central North America roughly 100 kilometers southwest of present-day Winnipeg and teemed with marine predators.
The shape of the perforations prevents scientists from isolating a single culprit. During the Cretaceous period, certain fish grew to such immense proportions that their teeth matched the dimensions of mosasaur teeth. Those giant marine reptiles ultimately vanished during the Cretaceous mass extinction roughly 66 million years ago, alongside non-avian dinosaurs.
Ruling Out Prehistoric Sharks
Although the seaway hosted massive prehistoric sharks, the research team quickly dismissed the possibility that a shark inflicted the wounds.
“We are practically certain it’s not a shark,” Brink said, noting that shark teeth feature a very different morphology and tend to leave distinct characteristic marks on bone.
Preliminary results from the study are currently accessible online, with the official publication scheduled for release by February 2027.