A rhinoceros tooth fossil discovered in a karst sinkhole near the Changyang human fossil site in Changyang Tujia autonomous county, Central China's Hubei Province Photo: Jinmu News

A rhinoceros tooth fossil has been discovered in a karst sinkhole near  Changyang human fossil site in Changyang Tujia autonomous county, Central China's Hubei Province. The fossil is believed to be a rare remnant of the animals that coexisted with ancient Changyang humans, who lived about 195,000 years ago, Liu Ying, deputy curator of the Changyang Museum, told the Global Times on Wednesday.

"The discovery of this rhinoceros tooth fossil is of great significance," Luo Jianping,  Party branch secretary of the Changyang Museum, told the Global Times. "It not only provides physical evidence for studying ancient Changyang humans and the animal species alongside which they coexisted, but also offers crucial insights into local history, helps complete the puzzle of prehistoric ecosystems, and enriches the cultural heritage of the Yangtze River civilization."

According to Liu, the fossil was first discovered by local villagers while exploring tourism resources. They accidentally entered a long-sealed sinkhole located just 17 kilometers from the Changyang human fossil site. Inside the sinkhole, they found a spacious horizontal cave. The fossil was found lying on the ground within the cave.

The villagers who discovered the fossil noted that the tooth measured approximately 10 centimeters in length, making it significantly larger than those of cattle or pigs. Puzzled by its size, they contacted the Changyang Museum for further examination.

Researchers at the Changyang Museum identified the specimen as a rhinoceros tooth fossil, noting its high degree of fossilization - an indication that it had endured countless years beneath the earth. Notably, the sinkhole where it was found shares strikingly similar climatic and geographical conditions with the Changyang human fossil site.

"The unique karst landscape in Changyang, with its network of caves, sinkholes, and underground rivers, acts like a natural vault," Liu told the Global Times. "These conditions provide an ideal environment for preserving fossils, allowing ancient secrets to remain intact for millennia."

According to Liu, besides rhinoceros remains, fossils of other mammals have also been discovered in Changyang in the past, including elephants, pigs, and bamboo rats — species commonly found in southern China. The presence of coexisting animal fossils indicates that 100,000 years ago, Changyang had a warm and humid climate, with dense bamboo forests and open grasslands, providing a suitable habitat for large animals such as rhinoceroses and stegodons to thrive.

In 1956, a human maxilla (jawbone) fossil was discovered in Changyang. Identified by the Chinese Academy of Sciences, the fossil was determined to be a Changyang human fossil, an ancient human who lived approximately 195,000 years ago. The discovery significantly elevated the study of human origins in the Yangtze River civilization. It also provides strong evidence that, like the Yellow River civilization, the Yangtze River civilization is a crucial source of the Chinese nation, according to Jimu News.

According to the Changyang Museum, the discovery of the Changyang human fossil provided key evidence for studying climate of the Yangtze River Basin in antient time by linking fossil morphology with associated animal species. It also shed light on the mechanisms early humans used to adapt to the subtropical mountainous environment.

"The recently discovered rhinoceros tooth fossil is likely a valuable remnant of the animals that coexisted alongside ancient Changyang human," Liu noted.

The discovery of the Changyang human fossil appears to be a remarkable collision of history and reality, transforming ancient legends into tangible evidence. It further highlights the deep historical significance embedded in the land of Changyang, Liu remarked.