This is the first transitional species backed up by the fossil record that I remember learning about years ago. There is more, all it takes is the energy to go get books from the library, or at least learn abot evolution theory before attacking it. I guess it`s hard to get over the idea that all this research is done only to try and describe our origins and not merely the efforts of non-believers who have a bible in one hand and a slide-rule in the other.
It was not until 1979 that paleontologists had their first indisputable evidence about whale transition. Pakicetus was discovered by Philip Gingerich in Pakistan. Later, in 1995, Hans Thewissen found Ambulocetus. Whales with legs are now known from Pakistan, India, Egypt and the U.S.A.
It took less than 15 million years for the whale lineage to move from land, through shallow bays and coastal waters, to deep marine environments. By 40 million years ago whales had become essentially the animals we know today.
The evolution of whales involved much more than legs becoming flippers or vestigial organs. The fossil series demonstrates how their breathing apparatus changed, their ears changed and other body parts changed. If you are interested in detailed taxonomic descriptions, click on an animal illustrated at right to be taken to another website with that information.
Whales did not turn into fish. Inside every flipper is found the bones of the mammalian hand. They swim like otters by undulating the mammalian spine. The tail fluke is not a fish fin. Evolution works by modifying existing body plans to fit new conditions of life, and is often constrained by developmental pathways. No longer limited by gravity and strength of bones, whales could become giants of the sea.
To learn more about whale evolution and the many transitional forms, use the hotlinks in the text above or in the bibliography given below.
http://www.origins.tv/darwin/landtosea.htm#whales