The expert said: “These results extend the last known occurrence of the Middle Stone Age by a staggering 20,000 years.
“At the same time, work by colleagues in Senegal also suggested an equally late first occurrence of the Later Stone Age at around 11,000 years – younger than in most other African regions.”
So why did the Middle Stone Age last so long in this part of the African continent?
It is possible parts of West Africa were less affected by cycles of climate change.
This may have led to a more stable environment over long periods of time.
Dr Scerri said: “As a result of such stability, a finely tuned toolkit that had worked well for millennia might not have needed to change, regardless of the social complexity of the people who made the tools.”