Pakicetus

Pakicetus is the genus name of a proto-whale fossil, the first discovered ancestor of modern whales that is distinctly a transition from early artiodactyls to today's whales. Palaeontologists basically just call it a "whale". It is one of several recent finds of transitional fossils that clearly show an evolution of land mammals returning to life in the water.

History
Pakicetus lived more than 50 million years ago, during the Eocene, in what is today Pakistan. Locations of fossil finds suggest that Pakicetus may have hunted or lived partially in the ocean.

Discovery
Four species of Pakicetus fossils have been identified and named. Though partial fossils were found in the early 1980s, a complete fossil was not found until 2001. Pakicetus inachus was the first Pakicetus fossil taxonomically identified, in 1981, by P. D. Gingerich and D. E. Russell.

In creationism
Creationists really hate whale ancestor fossils. Answers in Genesis noted in 1996 that "Pakicetus consists of only a few skull fragments.(!)" When much more complete skeletal remains were found in 2001, AiG had nothing to say about the development. Jonathan Sarfati wrote for the Institute for Creation Research that "evolutionists" believed it was not at all like a whale, which is the opposite of the truth (though pakicetus was not like modern whales in that regard, but of course, creationists leave everything ambiguous).