Evolution of cetaceans

[Kai]

This definition states how cetaceans (whales and dolphins) evolved for the last fifty million years.. Around 50 million years ago, there was a completely terrestrial mammal called Pakicetus. Pakicetus would occasionally go to the river banks to catch and eat fish. This would require swimming skills. This eventually drove Pakicetus to evolve. The legs became suited for water, and it learned how to hold its breath longer. Pakicetus evolved into [Ambulocetus], which in turn evolved in Rodhocetus. Rodhocetus had limbs for diving, along with a blowhole, but had no purpose for land travel. Rodhocetus soon lost its hind legs and became Dorudon around 40 ma. Dorudon had [dorsal] fins and would give raise to many types of dolphins and whales in its future. The proof for the [evolution of cetaceans] is that they have a pelvic bone that remains where their legs had once been. That is it...