WASHINGTON -- A team of
anthropologists from US and China report the first discovery of a skull from a
"pygmy- sized" giant panda -- the earliest-known ancestor of the giant panda --
that lived in south China some two million years ago.
The ancestor of today's giant panda really was a pygmy giant panda, says
Russell Ciochon, University of Iowa professor of anthropology. Ciochon is a
co-author of an article published in the June 18-22 online edition of the
journal Proceedings of the National Academy of Sciences. Previous discoveries of
teeth and other remains made between 1985 and 2002 had failed to establish the
Ciochon says that the ancient panda (formally known as Ailuropoda microta, or
"pygmy giant panda") was probably about three feet (about 0.9 meter) in length,
compared to the modern giant panda, which averages in excess of five feet (about
1.5 meters) in length. Also, like it's modern counterpart, it lived on bamboo
shoots, as indicated by wear patterns recorded on teeth and specialized muscle
markings, indicating heavy chewing, on the skull.
The new find, made about 18 months ago in a south China karst cave by Chinese
researchers and co-authors Changzhu Jin and Jinyi Liu of the Chinese Academy of
Sciences, shows that the basic anatomy of the giant panda has remained largely
unchanged for millions of years.
Ciochon says that the skull -- about one-half the size of a modern-day giant
panda skull, but anatomically very similar -- indicates that the giant panda has
evolved for more than three million years as a separate lineage apart from other
bears and was adapted to eating bamboo very early in its development.
"Pandas are very unique bears -- the only bear species that is known to exist
wholly on a vegetarian diet," says Ciochon. "The evolution of this unique
dietary specialization probably took millions of years to refine. Our new
discovery shows the great time depth of this unique bamboo-eating specialization
in pandas. Thus, pandas have been 'uniquely pandas' for many millions of years,"
Researchers say that the find further helps establish conditions that existed
in the region during the varying climatic conditions of the Pliocene and
Pleistocene epochs, stretching back some three millions years before the
present. The pygmy giant panda lived in lowland tropical bamboo forests. It is
often found associated with the extinct elephant-like creature, Stegodon, and
the giant extinct ape, Gigantopithecus. Today's giant panda is isolated in
mountainous upland bamboo forests, partly due to the pressure of modern