100 million year old fossil of cannibalistic mosasaur

A mosasaur fossil from Angola contained the remains of three other mosasaurs in its stomach, revealing the cannibalistic habits of the prehistoric ocean lord.

Reconstructed shape of a prehistoric mosasaur. Photo: NRP

The extinct marine reptiles that ruled the Earth's oceans during the late Cretaceous period have fascinated scientists since they were discovered in 1766 near Maastricht, the Netherlands. The fearsome lizards are a famous symbol of microevolution, representing the emergence of an entirely new group of animals. Michael Polcyn, a paleontologist at Utrecht University, has conducted the most comprehensive study of their early evolution, ecology and feeding habits. With the help of advanced imaging technology, his discovery provides new insights into the origins, relationships and behaviour of giant ancient lizards, Interesting Engineering reported on December 13.

Mollusks first appeared in marine environments about 100 million years ago, similar to the ancestors of modern whales. Over their 34 million-year history, they evolved into agile marine predators, filling a wide variety of ecological niches. Although they once dominated the oceans, they died out 66 million years ago in a mass extinction event caused by an asteroid impact.

Polcyn's research focuses on the little-known early evolutionary history of mosasaurs. Using micro-CT scans, Polcyn re-examines historical specimens and newly discovered fossils. The analysis reveals important anatomical details that help resolve debates about mosasaurs' ancestry and phylogenetic relationships. Polcyn's research confirms that mosasaurs are more closely related to monitor lizards than to snakes, as previously thought.

The study also revealed details about the mosasaur's feeding behavior. Among the most notable discoveries was a fossil from Angola that contained the remains of three other mosasaurs in its stomach, one of which belonged to the same species as the predator. But Polcyn couldn't say for sure whether the mosasaur was a scavenger or an active hunter.

In a broader analysis, Polcyn studied foraging patterns and the fragmentation of hunting grounds throughout the evolutionary history of mosasaurs. By integrating data from specimens from around the globe dating back 66 to 92 million years, he demonstrated that they divided up resources and adapted their foraging strategies over time. Polcyn's research is a powerful demonstration of how traditional paleontological methods can be combined with cutting-edge technology.