BBC: Primate archaeology is a new and unusual-sounding field, but it has revealed ancient evidence of some clever and dextrous monkey culture.
Researchers from Oxford University, working in Brazil, found ancient "nut-cracking tools" - 700-year-old stone hammers that capuchin monkeys used to open cashew nuts.
This is the earliest evidence yet of monkey tool use outside Africa.
The findings are published in the journal Current Biology.
One of the Oxford team, primatologist Dr Lydia Luncz, said...