How These Female Cavers Recovered New Human Ancestor Fossils (Exclusive Video)

Deep within a cave in South Africa, more than 1,200 individual bones of a new human ancestor, Homo naledi, were discovered. To recover the bones, six archaeologists had to rappel down underground shafts, combat carbon dioxide poisoning, and squeeze through rocky passageways as narrow as 18 centimeters (8 in).    

Read videographer Garreth Bird's journey filming the recovery of the Homo naledi fossils.