More than a hundred years ago, Sir Arthur Conan Doyle wrote a novel called The Lost World with the exciting premise that dinosaurs and other prehistoric beasts still ruled in South America. Little did Conan Doyle know, there were terrifying monsters in South America--they just happened to be extinct. In fact, South America has an incredible history as a land where many strange creatures evolved and died out. In his book Giants of the Lost World: Dinosaurs and Other Extinct Monsters of South America, Donald R. Prothero uncovers the real science and history behind this fascinating story. The largest animal ever discovered was the huge sauropod dinosaur Argentinosaurus, which was about 130 feet long and weighed up to 100 tons.