100 million year old fossil of cannibalistic mosasaur

Mosasaurs, extinct marine reptiles that dominated Earth’s oceans at the end of the Cretaceous period, have attracted the attention of scientists since they were discovered in 1766 near Maastricht, Netherlands. This fearsome lizard is a famous symbol of microevolution, revealing 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 aid of advanced imaging technology, his findings provide many new insights into the origins, relationships and behavior of ancient giant lizards, Interesting Engineering reported on December 13.

Mosasaurs first appeared in the marine environment about 100 million years ago, similar to the ancestors of modern whales. Over a history of more than 34 million years, they evolved into agile marine predators, spreading into diverse ecological niches. Although they once dominated the oceans, they still perished 66 million years ago in a mass extinction event caused by a meteorite 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 results reveal many important anatomical details, helping to resolve debates about the ancestors and phylogenetic relationships of mosasaurs. Polcyn’s research confirms that mosasaurs are more closely related to monitor lizards than snakes as previously thought.

The research process also revealed details about the mosasaur’s feeding behavior. Among the most notable finds is a fossil from Angola. This specimen contained the remains of three other mosasaurs in its stomach, one of which belonged to the same species as the predator. But Polcyn could not conclude with certainty whether the mosasaur was a scavenger or an active hunter.

In a broader analysis, Polcyn studied foraging patterns and the segregation of hunting grounds throughout the evolutionary history of mosasaurs. By integrating data from specimens across the globe from 66 to 92 million years ago, he demonstrated that they divided resources and adjusted their feeding tactics over time. Polcyn’s research demonstrates the effectiveness of combining traditional methods in paleontology with cutting-edge technology.