A newly discovered whale that lived nearly 40 million years ago could be the heaviest animal to have ever lived, based on a partial skeleton found in Peru, scientists said on Wednesday.

If so, be happy that you weren't around 40 million years ago. Back then, Europe's climate was warmer and more humid, which provided favorable conditions for gnats, among other things. One of these ...

but lived 195 million years ago in the Early Jurassic period. Called Hadrocodium wui, the little creature had certain key mammalian features 40 million years earlier than had previously been known ...

It also used its tail for swimming. Further along this evolutionary journey we find Dorudon, which lived 40 to 33 million years ago. This five-metre-long animal had proper flippers and tiny hind legs.