Paleontologists already suspected that Basilosaurus fed on large fish and other whales. Gut contents from another Basilosaurus species - Basilosaurus cetoides - showed this whale ate sharks and large fish.

Was Basilosaurus a carnivorous?

Roaming the seas some 41 to 34 million years ago was the Basilosaurus, a formidable prehistoric carnivorous whale from the late Eocene Originally thought to have been a monstrous reptilian creature, later evidence revealed that it was instead an early marine mammal.

What killed Basilosaurus?

Basilosaurus was a specialized type of animal that did not give rise to any later whales. Abrupt global cooling of the Earth's climate at the end of the Eocene coincided with changing ocean circulation. This led to the extinction of Basilosaurus and most archaic whales around 34 million years ago.