Which dynasty is the earliest extant original in China?

The existence of calligraphy has gone through different development periods, and the writing carrier on which it relies has also undergone great changes. I don't know which one you mean, so I summed it up one by one.

From the primitive pottery, there is the embryonic form of words; To Oracle Bone Inscriptions, Shang Dynasty; Then to the bronze inscriptions of Shang and Zhou Dynasties; Later, there were bamboo slips and silk books during the Spring and Autumn Period and the Warring States Period of the Zhou Dynasty. There are also inscriptions carved on stones, which prevailed in the Southern and Northern Dynasties and the Sui and Tang Dynasties. Many of them are representative works of calligraphy. Only after the emergence of paper in the Eastern Han Dynasty did the original paper calligraphy really come into being.

1) Painted pottery with a simple description of similar characters was unearthed at Banpo site of Yangshao culture about 6000 years ago. These symbols are distinguished from patterns, which promotes the development of Chinese characters. This can be said to be the origin of China characters. Then Erlitou culture and Erligang culture. In the archaeological excavation of Erlitou culture, there are 24 kinds of marked pottery pieces, some of which are similar to Oracle Bone Inscriptions in Yin Ruins, and all of them are single independent characters.

2) Oracle Bone Inscriptions, discovered in 1889, is a record of royal divination in the late Shang Dynasty. It was discovered more than 3000 years ago in Xiaotun Village, Anyang, Henan Province. Oracle Bone Inscriptions is the first treasure in the history of China's calligraphy.

3) Bronze inscriptions are also called Zhong Dingwen, Wen Qi and ancient prose. The lines of inscriptions cast together with bronzes are more vigorous than those of Oracle Bone Inscriptions, and the pictographic meaning of characters is more dense. The earliest inscriptions on bronzes were found on bronzes unearthed in the middle of Shang Dynasty. Although there were few materials, they all predated Oracle Bone Inscriptions in Yin Ruins.

4) The earliest archaeological discoveries of bamboo slips and silks include the Qin bamboo slips of the Warring States period unearthed in Yunmeng, Hubei Province, the book of the Warring States League unearthed in Houma, Shanxi Province (that is, the book of the League was written on a stone strategy or a jade strategy), and the silk book of the Warring States period unearthed in Mawangdui, Changsha.

5) Stone carvings originated in Zhou Dynasty and flourished in Qin Dynasty. So far, the earliest stone inscriptions in the Eastern Zhou and Qin Dynasties have been discovered. On the 10 granite drum stone, there is a four-character poem, which praises Qin's hunting, so it is also called hunting.

6) The earliest original calligraphy that can be seen today should be "Pingtie" by Lu Ji in the Western Jin Dynasty.