So let’s just get this out of the way right off the back: the Xia Dynasty, at least as it’s as written about by Sima Qian, did not exist, or is at least highly fictionalized. It’s a whimsical fairy tale in the same vein as the pre-Xia mythos of gods, demi-gods, cataclysmic forces, 9 suns being shot out of the sky, and emperors reigning for centuries. The founding emperor of Xia, so the tale goes, was the last of the 5 superhuman Sage-Kings. Historian Kwang-Chih Chang writes in the Cambridge History of Ancient China, “[…] was [there] indeed a ‘Xia dynasty’ at the head of Chinese history? In a traditional Chinese historiography, this could not be questioned, because the sequence of the Three August Ones, the Five Emperors, and the Three Dynasties lay at the root of every educated Chinese person’s idea of the beginning of Chinese history.” That only actually began to change starting in the 1920s, when a somewhat “renegade” segment of Chinese historians began to question the historical basis of these ancient supposed histories. This, in fact, led to the formation of an organization which called itself the rather scandalous name, Yigu Pai, meaning “The School of Doubting Antiquity.”
But as you say, it’s well understood that there were people living in the area of millennia prior to the historical Shang Dynasty attested to by the oracle bones. archaeological findings consistent with this period that show distinct urbanization, bronze tools and weapons, tombs suggesting ritual burial practices, and even large palaces uncovered in western Henan province. This ancient culture is known as the Erlitou Civilization – and there are strong indications that these may have been the people on whom the story of the Xia Dynasty would later be based. Both the period of the Erlitou – radiocarbon dated as existing between 2100 and 1800 BCE – and its location in China – centered in the Yellow River Valley – are consistent with the accounts of the Xia Dynasty. Moreover, as Chang puts it, “since the genealogy of the Shang dynasty given in the Shiji has been essentially validated by the newly discovered oracle-bone inscriptions, there would seem to be good reason to accept its genealogy of the Xia dynasty as well.”
Nevertheless, in spite of the basic acceptance of the premise of the Xia, the traditional idea of the Xia, Shang, and Zhou being sequential – as in one after the other, after the other – is increasingly viewed as inappropriate. A wide consensus has been reached that, in all likelihood, the three ancient dynasties were to at least some extent overlapping and co-extant civilizations, perhaps the three most powerful of the so-called “10,000 states” of the ancient past. It seems that in the course of the compiling of the ancient tales and histories in order to make his earliest chapters of the Shiji, Grand Historian Sima opted to pick-and-choose and create something of an amalgam of what little evidence there was of what was to him already long ancient and dead cultures.
Archaeological findings confirm the existence of at least 8 regionally-powerful Neolithic cultures across China, with many other within their respective orbits. As of circa 5,000 BC, the middle reaches of the Yellow River, most of modern Henan province, had a very powerful and wide-ranging culture known as the Yangshao, while the lower reaches of the Yellow R. in Shandong peninsula had another called the Dawenkou. These two are the most obvious basis for the stories of the Xia Dynasty. The Yangshao was characterized by ceramics of “reddish color and are painted with various designs in dark brown. Major vessel types include the bowl, water bottle, jar, and urn.” They were primarily millet farmers that lived in lineage units of well-laid-out villages, and appear to have been shamanistic. Their art tends to be “x-ray” or skeletal in nature, and is replete with instances of bisexualism. There is even some evidence that their religious practices may have formed part of the basis of the development of Daoism – in particular, burial practices involving arranging shells in the shapes of tigers and dragons alongside the deceased – in Daoist thought, those animals are often used to transport the initiated to Heaven to meets with the deities.
The Dawenkou also were millet farmers with ornate burial practices as well. These include elongated pit-graved, with a secondary hole dug in the middle to contain the actual coffin. The upper levels were then richly furnished with pottery, bone and ivory utensils, ritual instruments like rattles, and bone carvings – likely understood as necessary to the individual’s afterlife. It is from the Dawenkou that the eventually “classic” Chinese tripod design seems to have originated, and later been transmitted to the easternmost reaches of the Yangzhao as well, strong indicating their contemporary existences.
Down in the south around this same period (c. 5000-3000 BCE) on the lower reaches of the Yangtze River (surrounding mod. Shanghai, and Jiangsu and northern Zhejiang Provinces) there were two other cultures known as the Majiabang and the Hemudu cultures. These were both very early adopters and growers of rice, as well as the region’s abundant freshwater plants including water caltrop, fox nut, lotus seed and stem, water spinach, cattail, and rush. Archaeological findings also show abundant remains of fish, shellfish, dog, pig, and water buffalo. Their structures were wood and built along lake and rivershores on stilts to protect against floodwaters. Pottery among the Majiabang is – like the Yanshao and Dawenkou, primarily brown. But the Hemudu are interesting in that their pottery is black. Needham writes of the Hemudu: “Even the earliest cultural stratum showed signs of considerable technological sophistication, including well-made, finely decorated pottery and complex carpentry work, and the sheer volume of rice remains shows that the inhabitants were not proto-farmers but relied heavily on rice for food supply.” These southern cultures were not in any kind of regular communication or interaction with the Yellow River Valley civilization, but they and others including the Daxi of Sichuan, the Dapenkeng of Guangdong, Fujian, and Taiwan, the Dalongtan of Yunnan, and the Xinle culture of the Liaodong region to the northeast all put lie to the traditional Chinese telling of all culture and civilization being centered along the Yellow River and flowing outward to the surrounding primitives.
Chang, Kwang-chih. “China on the Eve of the Historical Period” in The Cambridge history of Ancient China.
Bray, Francesca. “Crop systems: Rice” in Science and Civilisation in China, Volume 6: Biology and Biological Technology, Part II: Agriculture.