One example involves a pair of splendidly realized gilt bronze leopards, their spotted bodies curled up and eyes set with ruby stones. The Han people liked to place themselves in a kneeling position, and the leopards, designed as mat weights, would keep the mat from moving as the sitter shuffled. They belonged to Liu Sheng (165-113 BC), a Han Dynasty vassal king who was the half brother of Emperor Wudi, the man who was behind the opening of the Silk Road.

The leopard can also be found on a gilt silver plate unearthed in Gansu and dated to somewhere between the fourth and sixth century. On the animal's back sits Bacchus, the Roman equivalent of Dionysus, a fact that has led researchers to attribute the beautifully wrought plate to craftsmen from the Byzantine Empire.

"By connecting the dots, you get a line of not only the trade route but also the two-way flow of culture," Li says.

Another animal that left its paw prints on the cultural history of ancient China was the lion. The ferocious beast, native to today's India and Iran, is believed to have first entered Han China through the Silk Road, and was soon adopted as a decorative motif. The inside center of a Tang Dynasty silver bowl unearthed in Xi'an was occupied by a pair of confronting lions, highlighted by gilding.