Oracle Bones

Oracle bones are pieces of bone or turtle plastron (underside) bearing the answers to divination chiefly during the late Shang Dynasty. They were heated and cracked, then typically inscribed using a bronze pin in what is known as oracle bone script. The oracle bones are the earliest known significant corpus of ancient Chinese writing, and contain important historical information such as the complete royal genealogy of the Shāng dynasty. These records confirmed the existence of the Shāng dynasty, which some scholars, until then, had doubted ever existed.

The oracle bones are mostly tortoise plastrons (ventral or belly shells, probably female) and ox scapulae (shoulder blades), although some are the carapace (dorsal or back shells) of tortoises, and a few are ox rib bones, scapulae of sheep, boars, horses and deer, and some other animal bones. The skulls of deer, ox skulls and human skulls have also been found with inscriptions on them, although these are very rare, and appear to have been inscribed for record-keeping or practice rather than for actual divination; in one case inscribed deer antlers are reported, but Keightley (1978) reports that they are fake. Neolithic diviners in China had long been heating the bones of deer, sheep, pigs and cattle for similar purposes; evidence for this in Liáoníng has been found dating to the late fourth millennium BCE. However, over time, the use of ox bones increased, and use of tortoise shells does not appear until early Shāng culture. The earliest tortoise shells found which had been prepared for oracle bone use (i.e., with chiseled pits) date to the earliest Shāng stratum at Èrlĭgāng (Zhèngzhoū, Hénán). By the end of the Èrlĭgāng the plastrons were numerous, and at Ānyáng scapulae and plastrons were used in roughly equal numbers. Due to the use of these shells in addition to bones, early references to the oracle bone script often used the term 'shell and bone script', but since tortoise shells are actually a bony material, the more concise term "oracle bones" is applied to them as well. (wikipedia)