The first human settlement on Russia dates back to the Oldowan period in the early Lower Paleolithic. About 2 million years ago, representatives of Homo erectus migrated to the Taman Peninsula in southern Russia. Flint tools, some 1.5 million years old, have been discovered in the North Caucasus. Radiocarbon dated specimens from Denisova Cave in the Altai Mountains estimate the oldest Denisovan specimen lived 195–122,700 years ago. Fossils of Denny, an archaic human hybrid that was half Neanderthal and half Denisovan, and lived some 90,000 years ago, was also found within the latter cave. Russia was home to some of the last surviving Neanderthals, from about 45,000 years ago, found in Mezmaiskaya cave.