Chinese archaeologists studying ancient rock carvings say they have evidence that modern Chinese script is thousands of years older than previously thought.State media say researchers identified more than 2,000 pictorial symbols dating back 8,000 years, on cliff faces in the north-west of the country. They say many of these symbols bear a strong resemblance to later forms of ancient Chinese characters. Scholars had thought Chinese symbols came into use about 4,500 years ago. The Damaidi carvings, first discovered in the 1980s, cover 15 sq km (5.8 square miles) and feature more than 8,000 individual figures including the sun, moon,...