ZURICH, SWITZERLAND—According to a statement released by the University of Zurich, three leather balls recovered from graves in the Yanghai ancient cemetery in northwestern China have been analyzed by an international team of researchers. Two of the balls were found in the graves of horsemen. A composite bow was also found in one of these graves. Patrick Wertmann of the University of Zurich said that the balls, which measure between about three and three and one-half inches in diameter, have been dated to between 3,200 and 2,900 years old, and are therefore about 500 years older than the previously oldest-known balls in Eurasia. Curved sticks have also been unearthed at Yanghai, but they are not as old as the leather balls, he added. The presence of the balls in the graves suggests that ball games may have been part of military training, Wertmann explained. To read about the remains of small donkeys unearthed in a Tang noblewoman's tomb, go to "Prized Polo...Donkeys?"