91福利社

David Attenborough has always been fascinated by fossils; even as a boy he'd spend many hours exploring the local quarry near his home in Leicestershire.

Near the family home was a forest he visited frequently, but he didn't hunt for fossils there. He thought the rocks were too old to have any postcards of early life embedded in their layers.

But he was wrong - those rocks harboured a wonderful secret - a secret that would rattle the cages of the big thinkers of the time and would change the story of life on earth forever....

Written and presented by Sir David Attenborough.

Producer: Julian Hector

First broadcast on 91福利社 Radio 4 in March 2011.