Penguins haven't always lived on ice, scientists have concluded after unearthing fossils of giant penguins in Peru's Atacama desert. The penguins, nearly human-sized at 4.5 feet tall, had extraordinarily long beaks apparently used for spearfishing, and waddled the earth some 36 million years ago, the National Geographic News reports.
A second new species of penguin, dating 42 million years ago, has also been discovered in the same area, standing about 3 feet tall—the size of modern-day king penguins, the second-largest surviving breed. While the discoveries challenge conventional wisdom about penguins' climate adaptability, scientists cautioned that modern birds remain extremely vulnerable to global warming. (More science stories.)