BEIJING, Feb. 17 -- The traditional Chinese zodiac attaches one of 12 animal signs to each lunar year in a cycle. But the coming lunar year of "yang", which starts on February 19, is still subject to debate over whether it means "sheep" or "goat".

Although Chinese are yet to decide definitively whether the animal symbol for the coming Lunar New Year should be a sheep or goat, archaeologists know which animal the Chinese began farming first.

China's earliest domesticated sheep was found in northwest China's Gansu and Qinghai provinces, dating back 5,600 to 5,000 years. Sheep breeding spread from west to east along the Yellow River basin, says Yuan Jing, a researcher with the Institute of Archaeology of the Chinese Academy of Social Sciences.

China's earliest known domesticated goat was found in the Erlitou relic site in the central China's Henan Province, dating back about 3,700 years, says Yuan, who focuses on animal archaeology.

It's commonly accepted in international academic circles that domesticated sheep and goats both originated in what is now Iran some 10,000 years ago.

Yuan says some Chinese animals, such as dogs and pigs, were domesticated locally, while others were introduced from abroad. Ancient Chinese began to tame wolves into dogs some 10,000 years ago, and domesticated pigs about 9,000 years ago.

"After that, it seems our ancestors tamed no other animals for a long time," Yuan says.

The farming of sheep came out of the blue.

In the 1970s, archaeologists found sheep bones dating back 5,600 to 5,300 years in a relic site in Shizhao Village, in Tianshui City, Gansu, and a whole skeleton of sheep in a tomb dating back 5,300 to 5,000 years in Qinghai's Minhe County.