In Egypt's Sahara Desert, massive skeletons with strangeskulls and gigantic teeth jut out from the sandy ground. Thisfossil graveyard, millions of years old, is known as the"Valley of the Whales." Now, paleontologists have unearthed awhole new species of ancient whale dating to 43 million yearsago, and this predator wasn't just able to swim – it alsohad four legs and could walk. Follow scientists as they searchfor new clues to the winding evolutionary path of mammals thatmoved from the land into the sea to become the largest animalson Earth.
