A gigantic fossilized skull that was hidden in a well in China for 90 years has just been discovered by scientists — and it's making them rethink human evolution. The remarkably well-preserved fossil has been labeled a new human species, Homo longi, by Chinese researchers. The species has been dubbed "Dragon man," for the northern Chinese province where the skull was found, Heilongjiang — or in English, the "Black Dragon River" region.