Whoa, I had no idea that they were water, to land, and then back to water.
Fossil hunters have discovered the remains of the earliest ancestor of the modern whale: a small deer-like animal that waded in lagoons and munched on vegetation.
The latest discovery, named Indohyus, is the first whale ancestor known to have lived on land.
The first whales, Pakicetidae, emerged around 50m years ago and resembled land mammals rather than the giant marine creatures of today. These evolved into large, powerful coastal whales, or Ambulocetidae, that had big feet and strong tails. Later, whales lost their hind limbs and hair and developed powerful tail fins and flippers.
Whoa, I had no idea that they were water, to land, and then back to water.
That last part is convergent evolution for water movement.
Some current whale species still have internal bones which are vestigial legs.