Nature
Wild monkeys have their own 3,000-year-old Stone Age, dug up by archaeologists
Bearded capuchins in Brazil's Serra da Capivara National Park still crack cashew nuts by pounding them with stone hammers on stone anvils. Excavating beneath their cracking sites, researchers found generations of discarded stone tools stretching back 3,000 years — the oldest non-human tool-use site known outside Africa, showing the monkeys' toolkit changing size and shape over time.