Photo taken on Aug. 17, 2020 shows the Mesopithecus fossils unearthed from Zhaotong, southwest China's Yunnan Province. Scientists from China, the United States, Greece and Australia have confirmed the discovery of a collection of Mesopithecus fossils dating back about 6.4 million years in southwest China's Yunnan Province. (Photo by Yang Xin/Xinhua)

Scientists from China, the United States, Greece and Australia have confirmed the discovery of a collection of Mesopithecus fossils dating back about 6.4 million years in southwest China's Yunnan Province.

The collection included a lower jaw, a partial femur and a complete calcaneus.

Two papers on the study have been separately published in the Journal of Human Evolution recently.

The fossil elements, located near Zhaotong City, were unearthed in 2009 and 2010. Their location represents the easternmost fossil record of the species reaching Eurasia, and they were also the first discovery of the genus in East Asia, according to Nina Jablonski, the first and corresponding author of one paper, from Pennsylvania State University.

Analysis suggests that the fossils from Zhaotong comprise a nearly complete mandible of a female Mesopithecus, weighing about 7.11 to 7.26 kg, according to Dionisios Youlatos, one of the corresponding authors of another paper, from Aristotle University of Thessaloniki, Greece.

The Mesopithecus fossils also confirmed that the ancestors of Asian snub-nosed monkeys should be ancient primates similar to Mesopithecus, said Ji Xueping, one of the paper authors and a researcher with the Yunnan Institute of Cultural Relics and Archaeology. 

File photo taken on Aug. 19, 2011 shows a black snub-nosed monkey, also known as the Yunnan golden monkey. Scientists from China, the United States, Greece and Australia have confirmed the discovery of a collection of Mesopithecus fossils dating back about 6.4 million years in southwest China's Yunnan Province. (Photo by Long Yongcheng/Xinhua)

File photo taken on Nov. 11, 2009 shows the Mesopithecus fossils unearthed from Zhaotong, southwest China's Yunnan Province. Scientists from China, the United States, Greece and Australia have confirmed the discovery of a collection of Mesopithecus fossils dating back about 6.4 million years in southwest China's Yunnan Province. (Photo by Wang Yi/Xinhua)