A dinosaur was the largest animal to exist on Earth, right? Wrong The largest animal in Earth's 4.7-billion-year history exists today: the enormous Blue Whale that swims the oceans. Come along on an evolutionary journey of 50 million years as we learn other remarkable facts and follow the ancestors of today's cetaceans from the time they crawled out of the oceans and then back to become the magnificent beasts we admire in every ocean on our planet...