■Second stand
Recently, a paper entitled "Clay Mineralogy Instructs Miocene Paleontine Apes to Live in Warm and Humid Environments in the Zhaotong Basin of Yunnan, China" was published in the nature publishing group's sub-journal Scientific reports, which for the first time elaborated on the reasons and mechanisms of the Zhaotong Basin as the last refuge of Miocene paleontine apes in Eurasia after the extinction of paleontines in Eurasia and other regions. The paper also made the Zhaotong ancient ape, known as the "last ancient ape", once again attract the attention of the archaeological community at home and abroad. So, is the Zhaotong ancient ape the ancestor of humans? Why can Yunnan Zhaotong become the last refuge of ancient apes?
Discover the Ancient Ape of Zhaotong
From October to November 2009, Ji Xuepingren, a researcher at the Yunnan Institute of Cultural Relics and Archaeology, excavated the fossil site of paleontological organisms at the coal mining yard of the Shuitangba Brick Factory near Zhaotong Airport. On November 4, they discovered a fossil skull of an ancient ape that was later colloquially known as the Zhaotong Ancient Ape (officially known as Lufeng Ancient Ape Lufeng Species Similar Species). According to paleomagnetic determination by the Institute of Geology and Geophysics of the Chinese Academy of Sciences, the age of Zhaotong paleontology is 6.2 million to 6.1 million years ago at the end of the Late Miocene, which is the latest Miocene paleocene ape remains in Eurasia.
Studies have shown that 17-15 million years ago, Miocene paleontine apes flourished in Eurasia and Africa, and their numbers began to decrease sharply after the late Miocene. Since the 19th century, fossils of the genus Siva ancient apes dating from 12.5 million to 8.5 million years ago have been found in the Sivarik Mountains of the Indian subcontinent. In the 20th century, the fossils of Kai ancient ape, Lufeng ancient ape and Yuanmou ancient ape were discovered in Yunnan, China, dating from 12 million to 7 million years ago. Ancient apes in other parts of Eurasia appear to have disappeared 7 million years ago.
The surprise appearance of the Zhaotong ancient ape has brought the survival age of the ancient ape in Eurasia closer to 6 million years ago. However, why did the last ancient apes survive in the Zhaotong region of Yunnan 6 million years ago, when all the ancient apes in other parts of Eurasia were extinct? Why did the Zhaotong area become the last refuge of ancient apes?
Uncover the secrets of the Final Refuge
Since 2013, Zhang Chunxia, associate researcher of the Institute of Geology and Geophysics of the Chinese Academy of Sciences, has made three field trips to Zhaotong, Yunnan Province, and together with researchers Ji Xueping, conducted in-depth research on the ancient ape and its living environment, obtained the guidance of academician Guo Zhengtang and academician Zhu Rixiang of the Chinese Academy of Sciences, and compared with the analysis and comparison of ancient ape locations in other parts of the world, finally unveiled the secret behind the Zhaotong area becoming the last refuge of ancient apes.
The research team conducted detailed clay mineralogy and pollenological studies on paleoenvironmental samples systematically collected on the profile of the Pond Dam in the Zhaotong Basin at the end of the Miocene. The fossils of the ancient ape were found in the peat layer between the coal seams, and their sedimentary facies were similar to the sedimentary facies (such as coal seams, interco-seam clay layers or peat layers) at the excavation sites of ancient ape fossils in Kaiyuan, Lufeng, Yuanmou and Baoshan in Yunnan, and the results of clay mineralogy and sedimentary phase analysis showed that Zhaotong ancient apes lived in warm and humid lake and marsh environments.
In order to further obtain the reasons why Yunnan, especially the Zhaotong Basin, was the final refuge of the Mesocene Zhaotong ape in Eurasia, the research team compared the fossil sites of Yunnan paleontines with the flora of the Miocene paleontine sites in the West Walic region and Africa, and systematically compared the relevant results such as carbon isotopes. The results show that the ecological transition from forest to grassland in the West Warik region is much later than in Africa, while Yunnan, located on the southeastern edge of the Qinghai-Tibet Plateau, has been dominated by tropical and subtropical forests throughout the Late Miocene period, and the ecological environment has not changed significantly. This tropical and subtropical forest was not gradually replaced by dry and cold coniferous forests until the middle of the Pliocene, 4 million to 3 million years ago.
The research team therefore believes that the joint effect of the uplift of the Qinghai-Tibet Plateau with the formation of the Asian monsoon climate and the global climate cooling has enabled Yunnan to form a relatively independent humid and hot environment area geographically and climatically, delaying the start of the dry and cold climate, enabling the Zhaotong ancient ape to have a long-term suitable geographical environment, providing a unique refuge for the Mesocene paleo ape in Eurasia, so that the Zhaotong ancient ape can survive until 6 million years ago.
The Zhaotong ancient ape is related to the origin of early humans
"Zhaotong ancient ape is related to the exploration of the origin of early humans in China, which is its most important value." Ji Xueping thinks.
At present, the mainstream academic view is that humans originated in Africa, the earliest human family in Africa appeared 6 million to 7 million years ago, and a large number of australopithecus were found in 2 million to 5 million years ago. Who the ancestors of the earliest members of the family Anthropocene in Africa were, and the academic community has not yet determined, while the Zhaotong ancient ape was discovered in 6 million years. The discovery of the Chotung ancient ape is extremely important for the study of human origins earlier than the early African family. Because 6 million years ago was a critical period of evolution from apes to humans, and Zhaotong ancient apes are the closest to the emergence of human ancient apes, and the humid and hot environment suitable for the survival of Zhaotong ancient apes has continued to more than 3 million years ago.
At the same time, the face of the Zhaotong ancient ape is basically intact, and the preservation condition is excellent, with only minor deformations. Through research, scientists found that the skull orbit of this ancient ape is rounded and square, and the width is greater than the height, the eyebrow ridge is obviously beginning to develop, the middle face is wide and short, and the degree of protruding jaw is weak, which makes the Ancient Ape of Zhaotong have some of the characteristics of the earliest human ancestors. However, due to its juvenile nature and the fact that only facial bones have been found, the understanding of the characteristics of this type of ancient ape is still very limited, and more discoveries are still needed. (According to Guangming Daily)
Editor-in-Charge: Anon