With pines up to 1.80 meters long and 4.5 times thicker than those of a Tyrannosaurus rex, the pliosaur could reach twice the size of a modern killer whale, weigh tens of tons, and eat every living thing in the water.
The fossil is about 10 meters long and was surrounded by ancient crocodile teeth and turtle shells. It is located in a tropical archipelago dotted with lagoons and reservoirs of warm water.
"This new area is rich in fossils of coastal and pelagic reptiles," the researchers wrote about the site in the northeastern part of the Holy Cross Mountains near the village of Krzyżanowice.
Read more: T. rex had such a hard skull that even T. rex could not break it, say scientists