A mosasaur tooth has been found at one of the most famous Late Cretaceous fossil sites in the world. That means the famous marine predators adapted to a freshwater environment, and it seems they ...

Learn how chemical clues reveal a mosasaur was hunting in freshwater rivers as the Cretaceous seaway receded.

Mosasaurs were enormous reptiles best known for ruling ancient oceans more than 66 million years ago, but new evidence suggests some also lived in rivers. Scientists reached this conclusion after ...

Mosasaurs, giant marine reptiles that existed more than 66 million years ago, lived not only in the sea but also in rivers. This is shown by new research based on analyses of a mosasaur tooth found in ...

At the end of the Cretaceous Period, a type of giant reptile called mosasaurs occupied and dominated oceanic food webs.

Experts think the creatures adapted to river environments in the final million years before they became extinct.

A surprising fossil find shows that some mosasaurs lived in ancient rivers as oceans changed near the end of the Cretaceous.

Giant mosasaurs, once thought to be strictly ocean-dwelling predators, may have spent their final chapter prowling freshwater ...

And while some mosasaurs were up to 10 meters long (33 ft), it was only about the size of a small porpoise. That said, its unique teeth likely allowed it to "punch above its weight." Whereas the teeth ...

A giant "sea dragon" backbone plucked from a riverbank in Mississippi could belong to the largest mosasaur ever found in the state, scientists say. Researchers only found a single vertebra from the ...