Traditionally the first appearance of the hand cannon is dated to the late 13th century, just after the Mongol conquest of the Song dynasty. However a sculpture depicting a figure carrying a gourd shaped hand cannon was discovered among the Dazu Rock Carvings in 1985 by Robin Yates. The sculptures were completed roughly 250 km northwest of Chongqing by 1128, after the fall of Kaifeng to the Jin dynasty. If the dating is correct this would push back the appearance of the cannon in China by a hundred years more than previously thought. The bulbous nature of the cannon is congruous with the earliest hand cannons discovered in China and Europe.