China News Service, Beijing, January 15 (Reporter Sun Zifa) Recent research results of Chinese paleoanthropologists continue to emerge, following the modern human traits of the Hualongdong people’s femur 300,000 years ago, and the abnormal traces of the skull bones of Hexian people 400,000 years ago. A study of four ancient human tooth fossils unearthed from Longgu Cave in Meipu County, Yunxian County, Hubei Province, found that the ancient human being lived nearly a million years ago, and evolved in the early Eurasian Homo erectus and the late typical Homo erectus from early to late The intermediate state of the transition.

The study model of 4 Meipu Homo erectus tooth fossil specimens nearly a million years ago.

Photo by Sun Zifa

The date is determined to be 780,000 to 990,000 years ago

　　Meipu Homo erectus age and tooth fossil morphology of the latest research results papers, recently published online in the international professional academic journal "Journal of Human Evolution".

　　Dr. Xing Song, a researcher at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (Institute of Paleontology, Chinese Academy of Sciences), who led the research, said that the site of the ancient humans in Meipu is located in the Dragon Bone Cave of Dujiagou, Meipu Town, Yun County, Hubei, in the Qinling Mountains The southern foot of the eastern section.

The field team of the Institute of Paleospine, Chinese Academy of Sciences learned of the Meipu fossil clues during an investigation in 1974. The following year, four ancient human teeth were discovered, along with a stone core and more than 20 mammalian fossils.

　　In order to further determine the age of the ancient human fossils in Meipu, the scientific research team led by the Institute of Paleospine of the Chinese Academy of Sciences went to Meipu Longgu Cave twice in 2016 and 2017 to conduct on-site research and collected 8 in-situ secondary carbonate samples and fossil layer paleo. After comprehensive determination of geomagnetic samples and combined with paleomagnetic analysis, the scientific research team determined the age of the ancient human fossil layer in Meipu as 780,000 to 990,000 years ago, reaching nearly one million years.

Meipu ancient human tooth dentin surface structure and geometric shape measurement of crown contour shape.

Photo courtesy of Xing Song

Teeth study finds intermediate state of Homo erectus evolution

　　Xing Songke said that the ancient human fossils discovered in China mainly include Homo erectus (also known as ape) and Homo sapiens. Among them, the era of Homo erectus spans nearly 2 million years. The representative Homo erectus are Yuanmou, Yunnan and Lantian, Shaanxi. People from Beijing, Zhoukoudian, Anhui and County, Homo sapiens include early Homo sapiens and late Homo sapiens, and late Homo sapiens has entered the modern stage.

　　He pointed out that the ancient human fossils in Meipu were originally classified as Homo erectus, but due to the limitations of comparison specimens and research methods at that time, their position in the evolutionary sequence of Homo erectus has not been studied in detail.

To this end, based on traditional morphological observations, the scientific research team used advanced methods such as micro-CT and geometric morphology to re-study the morphology of the four human tooth fossils in Meipu. The characteristics of human teeth make it an intermediate state of the transition from early Homo erectus to late Homo erectus.

Meipu ancient human teeth.

Photo courtesy of Xing Song

Make up for the lack of understanding of the evolution of ancient humans in East Asia

　　The early Homo erectus fossils discovered in China are particularly scarce, and there has been a lack of in-depth understanding of the morphological characteristics and evolutionary status of Homo erectus at this stage.

　　Xing Song said that although the ancient humans in Meipu only found 4 tooth fossils, they are well preserved and the unearthed horizon is clear.

The research team's re-determination of the ancient human age in Meipu and the re-study of the fossil morphology, on the one hand, enabled the academic community to understand the evolutionary sequence of Homo erectus from early to late in East Asia.

　　On the other hand, linking the ancient Homo erectus of Meipu with the early Homo erectus in Eurasia and even members of the early Homo genus in Africa and the late Homo erectus discovered in East Asia "to a certain extent made up for the scarcity of materials and poor preservation conditions, As a result, our understanding of the characteristics and evolutionary status of the early Pleistocene ancient humans in East Asia is insufficient."

Provide evidence of the earliest right-handed use of ancient humans in East Asia

　　Xing Song revealed that prior to this, the scientific research team had also found many cutting marks on the lip side of the incisors of ancient humans in Meipu.

Studies have shown that these marks are caused by ancient humans using their teeth and one of their hands to fix objects (such as food), and the other hand accidentally touching the surface of the teeth during the cutting process.

The direction of the cutting marks caused by the right-hand and left-hand tools is different. By analyzing the orientation of these cutting marks, it is possible to infer which hand-held tool (dominant hand) was used by ancient humans at that time.

　　The results of the study show that the cutting marks on the surface of the incisors of the ancient humans in Meipu (at least 2 individuals) are mainly oriented from the upper left to the lower right, reflecting the cutting with the right hand tool.

Therefore, the scratches and directions on the front teeth of Meipu ancient humans provide evidence of the earliest right-handed right-handed ancient humans found in East Asia.

　　It is reported that the study of Homo erectus in Meipu was conducted by Xing Song, Ge Junyi, Wang Yuan, Institute of Paleospine, Chinese Academy of Sciences, and Shao Qingfeng, Nanjing Normal University, in collaboration with Institute of Geology and Geophysics, Chinese Academy of Sciences, Hubei Provincial Institute of Cultural Relics and Archaeology, Yunyang Museum, and National Human Evolution Research Center of Spain. The collaboration was completed, and the "right-handed" paper was previously published in the International Journal of Skeletal Archaeology.

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