Dreadnoughtus, discovered in Patagonia, Argentina, is one of the largest titanosaurs ever discovered. A tale of human sacrifice deep within an underwater cave (or cenote) in Yucatán, Mexico, offers new insight into the rise and fall of the ancient Maya civilization. Draining Alaska's extreme north reveals the graveyard of a tragic fleet of 32 whaling ships strapped in the Arctic ice off the state's north coast in the Whaling Disaster of 1871.
