Researchers have long known that the ancestors of the mighty whales were nimble, four-legged creatures that were comfortable both on land and in the sea. However, given that the only evidence of the early mammals had been found in present-day Pakistan, India, and parts of Africa, scientists were unsure of how the mammals had dispersed to the Western Hemisphere. Now, thanks to the aptly-named Peregocetus pacificus (P.pacificus), or "traveling whale that reached the Pacific," paleontologists finally have an answer to this all-important migration mystery.