for National Geographic News
A fossil skull representing the earliest known species of panda has been discovered in China, researchers report.
The find shows that small-bodied, "pygmy" ancestors of the modern giant panda were present in the forests of southern China at least two to three million years ago.
The prehistoric panda's teeth and jaw indicate that the species, Ailuropoda microta, was already adapted to a diet of bamboo, just like the black-and-white giant panda of today, according to experts who examined the fossil.
Skull features also indicate that the early panda may have been remarkably similar to its endangered present-day descendents—but only about half the size. (Related: "Panda Sanctuary in China Named World Heritage Site" [July 18, 2006].)
"One can call the fossil species the 'pygmy giant panda,'" said Russell Ciochon of the University of Iowa. "It really is a miniaturized version of the living giant panda."
A few fossil teeth from A. microta had previously been found, but the creature's size remained a mystery until now. The first complete skull provides a far richer picture of the bear's biology, Ciochan said.
A team led by Changzhu Jin of the Chinese Academy of Sciences in Beijing found the skull embedded in the wall of a limestone cave in China's Guangxi Zhuang Autonomous Region.
The report by Jin, Ciochon, and colleagues appears in today's online edition of the U.S. journal Proceedings of the National Academy of Sciences.
Although giant pandas are technically classified as carnivores, the animals are unique among bears in having adopted an entirely vegetarian diet.
The new fossil proves that pandas' dietary preference for bamboo evolved quite early, Ciochon said.
"The panda lineage has been evolving for several million years totally separated from their traditional bear ancestry," he added.
SOURCES AND RELATED WEB SITES