New Study Reveals Prehistoric Shark Feeding Habits on Whales in North European Waters
A new study, led by the Institute of Natural Sciences in Brussels (RBINS), analyzed two fossilized whale skulls from approximately 5 million years ago. The study identified fragments of sharks' teeth lodged within the skulls, providing concrete evidence of how sharks fed on whales in prehistoric north European waters.
CT scans of the two skulls were used to determine the feeding methods. The scans revealed shark teeth that had broken off and become embedded in the whale skulls during feeding.
Dr. Olivier Lambert, a palaeontologist at the Institute of Natural Sciences and lead author, stated that the fossils offer insights into the termination of these whales' lives.
Ancient Discoveries in Belgium
Both skulls date from the Early Pliocene period, approximately 4-5 million years ago, and were discovered in Belgium. One skull, belonging to an extinct type of right whale, was found in the 1980s in the Antwerp docks by Professor John Stewart. The second skull, from a monodontid (a relative of modern beluga and narwhal), was found by Dr. Paul Gigase and his son Pierre.
CT Scans Uncover Hidden Details
Modern technology, specifically CT scans, revealed details within the skulls 40 years after Professor Stewart's discovery. Dr. Lambert indicated that the CT scans enabled shark identification without damaging the skulls. The position of bite marks on the right whale skull suggests the animal had likely died prior to the shark scavenging its carcass, and was in a belly-up position.
Identifying the Prehistoric Predators
The tooth fragment from Professor Stewart's whale was identified as belonging to a cow shark. The other skull contained a tooth fragment from a relative of the modern great white shark. Neither these ancient species nor their modern counterparts are found in the southern North Sea today.
Insights into Ancient Marine Ecosystems
These findings offer insight into the relationships between large predators and their prey off the coast of Northern Europe 5 million years ago. Professor Stewart highlighted that the study provides concrete evidence, including predator fragments, for palaeontologists to analyze.
Dr. Lambert commented that these skulls represent a step towards understanding historical changes in prey availability in the southern North Sea and the disappearance of large predatory sharks from the area. He also noted that ongoing climate change is altering marine mammal distribution, which may also impact predator distribution.