Scholars believe the Hongshan culture of Neolithic China, established some 6,500 years ago, may be the earliest Chinese kingdom. Now, in an attempt to gain insight into this ancient and mysterious culture, a team of researchers has investigated a region called the Hunshandake Sandy Lands of Inner Mongolia, where they found many Hongshan artifacts. The new study’s findings, published this week, suggest some surprising new conclusions about the fate of the Hongshan kingdom, and its importance in Chinese history.

Though it was long thought that Chinese civilization began in the Yellow River Valley region, historians now know that earlier cultures existed in other regions of China. One of the earliest known of these was the Neolithic Era’s Hongshan culture, whose members inhabited the lands between Inner Mongolia and today’s Liaoning and Hebei Provinces beginning around 6,500 years ago—a full 2,400 years before the rise of the Xia Dynasty, described in ancient historical chronicles as the first Chinese dynasty. Hongshan means “Red Mountain,” after a site in Inner Mongolia.

Archaeologists have excavated Hongshan sites all around northern China. According to researchers, the Hongshan were responsible for some of the earliest known examples of jade-working in China, including a fishlike jade creature believed to be the first Chinese symbol to resemble a dragon. Indeed, jade artifacts have sometimes been the only items found inside Hongshan tombs, indicating the importance of jade to their culture.

In their quest to understand more about the Hongshan culture, the researchers in the new study took a closer look at the desert belt located in northern China, specifically a region known as the Hunshandake Sandy Lands of Inner Mongolia, located some 185 miles (300 kilometers) west of Liaoning. Though earlier research concluded that the northern Chinese deserts date back some 1 million years, the new study’s findings suggest that the desert of Hunshandake is only about 4,000 years old.

The researchers found numerous and varied remnants of pottery and stone artifacts dating to the Hongshan era in Hunshandake, suggesting that the region was home to a dense population dependent on hunting and fishing for its livelihood. By analyzing changes to the environment and landscape of Hunshandake over the past 10,000 years, they found that rivers and lakes once dominated the region’s terrain, and that relatively deep water existed there between 5,000 and 9,000 years ago, along with vegetation including spruce, fir, birch, pine and oak trees.

Beginning about 4,200 years ago, the researchers found, a dramatic transformation occurred. According to their findings, published this week in the journal Proceedings of the National Academy of Sciences, more than 7,770 square miles (20,000 square km) of the Hunshandake area rapidly dried up and turned into desert. The scientists suggest that a river permanently diverted water from the region, around the same time that a major climactic shift worldwide created severe droughts on all the continents in the Northern Hemisphere. As study co-author Louis Scuderi, a paleoclimatologist at the University of New Mexico in Albuquerque, told LiveScience: “We think this drying happened in northern China as well, but was augmented by massive amounts of water getting diverted away from the area.”

Though the Hongshan have typically been seen as a remote culture far removed from the main cradle of the Chinese civilization in the Yellow River valley region, Scuderi and his colleagues say their conclusions suggest they may have been more important to the course of Chinese history than previously believed. The rapid desertification of Hunshandake, the researchers believe, devastated the Hongshan kingdom. As a consequence, its displaced members likely migrated throughout the rest of China, where they may have played an influential role in the birth of later Chinese civilizations.