These fossils, about six million years old, were discovered in Yunnan province in southwestern China. Among them is a particularly large wrist bone, called the “radial sesamoid”.
This is the earliest evidence for the existence of a
sixth finger in the giant panda, which allows it to grab and break thick bamboo stalks, the researchers pointed out in the latest edition of the journal Scientific Reports.
This fossil belongs to a now extinct panda ancestor called “Ailurarctos”, who lived in China between six and eight million years ago.
The giant panda is […] a rare case of a large carnivore […] become a herbivoresaid Wang Xiaoming, curator of vertebrate paleontology at the Los Angeles County Museum of Natural History.
” The Ailurarctos ‘fake thumb’ shows for the first time the chronology and probable stages of the evolution of bamboo feeding in pandas. »
If the existence of
fake thumb had already been known to researchers for about a century, the fossil evidence for this bone sheds light on several long-unanswered questions, including how and when this extra toe, which does not exist in any other bear, evolved.
Millions of years ago, pandas swapped the omnivorous, protein-rich diet of their ancestors for the nutrient-poor, year-round bamboo in southern China.
They eat for up to 15 hours a day and an adult panda can consume 45 kg of bamboo daily. Although their diet is primarily vegetarian, giant pandas are also known to occasionally hunt small animals.