Fossils show how panda's false thumb evolved

STORY: Did you know pandas have a 'false thumb'?

The veggie-loving bears have a thumb-like sixth digit on their wrists

which helps them munch the bamboo that makes up most of their diet

Recently unearthed fossils in China

are helping scientists better understand this evolutionary marvel

Researchers say they've discovered fossils about 6 million years old

of an extinct panda called Ailurarctos

They bear the oldest-known evidence of the improvised extra digit

It closely resembles the false thumb of modern pandas

but is a bit longer and lacks the inward hook present on the end

that provides greater ability to manipulate bamboo stalks and roots while eating

Quote box: "The hooked false thumb offers a tighter grasp of the bamboo and, at the same time, its less-protruded tip - because of the bended hook - makes it easier for the panda to walk."

"Think of the false thumb as being stepped on every time the panda walks. And therefore, we think that is the reason that the false thumb in modern pandas has become shorter, not longer." - Xiaoming Wang, Natural History Museum of Los Angeles County paleontologist