Recognizing the conundrum as one of the great challenges to his theory of evolution by ... a few million years whales had passed the point of no return:Basilosaurus, Dorudon, and their relatives ...

It also used its tail for swimming. An artist's impression of Dorudon, an ancestor of modern whales Further along this evolutionary journey we find Dorudon, which lived 40 to 33 million years ago.

As evolutionary biologist Neil Shubin points out, "In one sense, evolution didn't invent anything new with whales. It was just tinkering with land mammals. It's using the old to make the new." ...

Understanding human evolution through the study of whale evolution Brief definition and history of mammals How did land-based mammals return to the sea? Fossils from "transitional species" trace ...

And although the geologists didn’t realize it at the time, the prehistoric specimens in the sand would offer clues to one of evolution ... Dorudon looked more like a modern whale, at least ...