Fossils unearthed in China are helping scientists get a better grasp on one of the marvels of evolution: the giant panda's false thumb, which helps this veggie-loving bear munch the bamboo that makes up most of its diet.
Researchers said on Thursday they discovered near the city of Zhaotong in northern Yunnan Province fossils about 6 million years old of an extinct panda called Ailurarctos that bore the oldest-known evidence of this improvised extra digit - actually a greatly enlarged wrist bone called the radial sesamoid.
