There's a new titleholder for the biggest, baddest bear ever found. A prehistoric South American giant short-faced bear tipped the scales at up to 3,500 pounds (1,600 kilograms) and towered at least 11 feet (3.4 meters) standing up, according to a new study. The previous heavyweight was a North American giant short-faced bear -- a related extinct species -- that weighed up to 2,500 pounds (1,134 kilograms). The largest bear on record in modern times was a 2,200-pound (998-kilogram) polar bear shot in Alaska in the 19th century. The South American giant short-faced bear roamed its namesake continent about 500,000...