Imagine a five-eyed lobsterlike creature hovering above the ocean floor, bringing food to its mouth through a long, wormlike trunk tipped with spines. Is this on Mars? No, it's an Opabinia regalis, an ancient creature whose discovery originally caused paleobiologists to laugh, and just one of dozens of 3-D computer-animation and life-size models in the series. This episode examines the history of oceans, which are thought to be the cradle of life on earth. Descend into the deep of Earth's Ancient Oceans to witness the explosion of life preserved today in the British Columbia's Burgess Shale as bizarre Cambrian fossils and their fascinating reconstructions , and how life may have moved from water to land.