Fossils uncovered in Japan nearly two decades ago have revealed a giant salamander believed to have inhabited the region's lakes and marshes roughly 3.5 million years ago. "Ajimu contains the only site in the world where fossils of the giant salamander family and extant genera have both been found," the lead author, Masahiro Noda, said. Scientists initially believed the fossils belonged to a living giant salamander species, but further analysis revealed they represented a previously unknown genus and species, Limnospondylus ajimuensis. "Recently, Japan's native giant salamanders have faced challenges such as hybridization with foreign species and habitat destruction," Noda said. The discovery brings researchers one step closer to understanding the evolutionary history of East Asian giant salamanders.