Episode Title:Sabre Tooth.Episode Description:The fifth episode shows the strange fauna of the isolated continent of South America and explores the effects of the Great American Interchange, which had happened 1.5 million years earlier. Since South America had drifted apart from Antarctica 30 million years ago, many unique mammals had evolved, including the Doedicurus, an armored armadillo-like mammal with a cannon ball-sized spiked club on its tail; the Macrauchenia, a camel-like mammal with a long trunk; and the Megatherium, a giant ground sloth.