Snow leopards have been spotted in Beijing? Scientists reveal the secrets of snow leopards' unique evolution

The Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences recently announced that Associate Researcher Jiang Zuoqi Gao and his team, in collaboration with the Institute of Zoology of the Chinese Academy of Sciences and scientists from many European countries, have identified rare snow leopard fossils from fossil records found in Zhoukoudian, Fangshan, Beijing, Niuyan Cave, Mentougou, and other places, thus revealing the snow leopard's special evolutionary path. Currently, the relevant research results have been published in the internationally renowned academic journal Science Advances.

Snow leopards once left the Qinghai-Tibet Plateau

Jiang Zuoqigao said that today's snow leopard is a large cat species unique to the Qinghai-Tibet Plateau and its surrounding areas. As the top predator of the Qinghai-Tibet Plateau, the snow leopard is extremely important in maintaining the stability of the Qinghai-Tibet Plateau ecosystem. In addition, its unique appearance makes the snow leopard a flagship species for the protection of the Qinghai-Tibet Plateau ecosystem.

Previous studies have shown that snow leopards are most closely related to tigers in the evolutionary process. However, snow leopards and tigers have diverged further and further in evolution, with the former living in the harsh cold environment of the plateau, while the latter live in a relatively more common natural environment. The reason for this divergence has long been a difficult problem faced by the scientific community. The results of this study show that snow leopards have historically left the Qinghai-Tibet Plateau and appeared in places such as Beijing and Europe.

Jiang Zuoqigao introduced that as early as 80 or 90 years ago, Academician Pei Wenzhong had noticed a fossil found in Zhoukoudian and proposed the possibility that it was a snow leopard fossil. Later, some European scholars also believed that this fossil was a snow leopard, but there was a lack of systematic evidence, so it was not widely accepted internationally.

Hundreds of fossils have been identified

Before conducting the study, the research team had an in-depth understanding of the skeletal structure and other characteristics of modern snow leopards. Deng Tao, a researcher at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, co-corresponding author of the paper, said that in order to study the evolution of relevant morphological characteristics of snow leopards, the research team first combined traditional anatomy, geometric morphology, finite element analysis and other methods to conduct a systematic study of the functional morphology of modern snow leopards.

The results show that snow leopards have large eye sockets and highly developed binocular vision, indicating that they have developed stereoscopic vision and can quickly lock onto prey in complex terrain; snow leopards have short snouts and steep mandibular symphysis, and canine teeth with a nearly circular cross-section. The corresponding canine teeth can generate strong force and can deal with prey with strong resistance, but the price is lower flexibility.

In addition, the research team also found that snow leopards have a well-developed frontal sinus system, which can warm the air inhaled into the body and increase breathing efficiency, adapting to the high-altitude and low-oxygen environment; the well-developed pretympanic cavity of the auditory bulla enhances the sensitivity to infrasound, allowing it to hear the movements of prey at a farther distance in open areas; larger cheek teeth, which can quickly eat most of the meat before the prey carcass freezes in a cold environment, and have better chewing ability for frozen carcasses; smaller shoulder blades and pelvis, and very slender distal limb bones, which means they are relatively weak in strength but have very flexible athletic ability, adapted to running and jumping in the mountains.

Most of these characteristics are adaptations to the mountainous environment and to the subfamily of sheep as their main prey (sheep are relatively slow, but have short and thick limb bones, well-developed horns, and greater resistance), and only a small number are adaptations to the high-altitude, low-oxygen environment.

The five fossils identified this time were found in many places in Eurasia. In addition to Beijing Fangshan and Mentougou, one was found in Longdan, Gansu, and two were found in Portugal and France. During the research process, researchers investigated hundreds of fossils found in Eurasia, and finally found a number of fossil records suspected to be snow leopards. Combined with the analysis and comparison of the systematic development of Panthera, they finally confirmed that five of the fossils belonged to snow leopards, which were "small branches" that left the Qinghai-Tibet Plateau during the evolution of snow leopards.

In addition to snow leopard fossils, leopard fossils were also found in Niuyan Cave in Mentougou, Beijing, representing the only fossil site in the world where snow leopards and leopards coexist. Leopards and snow leopards occasionally coexist near the woodland line, so the discovery of fossils of both species at the same site is of great significance for studying the environment at that time.

No ancient human remains found at the fossil site

"Among them, the snow leopard fossils found in Gansu are about 2.2 million to 2.5 million years old, and the snow leopard fossils found in France are about 500,000 to 600,000 years old. The snow leopard fossils found in Zhoukoudian, Beijing may be 200,000 to 300,000 years old. The fossils found in Portugal and Mentougou, Beijing are all from the late Pleistocene, about 10,000 to 100,000 years old." Jiang Zuoqigao introduced that no ancient human remains have been found at the third site of Zhoukoudian, Fangshan, and Niuyan Cave in Mentougou, where snow leopard fossils were found. However, it is not impossible to find evidence of coexistence of snow leopards and humans in the future, but this requires further scientific research.

Jiang Zuoqigao said that the research shows that as early as 2.2 million to 2.5 million years ago, tigers and snow leopards began to take different paths in evolution. But 700,000 to 800,000 years ago, the Qinghai-Tibet Plateau experienced a significant uplift, and a large-scale ice sheet appeared. During the same period, the snow leopard also entered a period of rapid evolution, and after continuous evolution, it eventually formed the appearance of the modern snow leopard. "This study not only helps us understand the evolutionary history of snow leopards, but also helps us understand the evolutionary process of the Qinghai-Tibet Plateau ecosystem from a side perspective."

Providing important reference for the protection of snow leopards

The research team also noted that although the five snow leopard fossil sites in Central Europe studied this time may be at a very low altitude (less than 500 meters), they all belong to mountainous environments and basically have species of the subfamily Caprinae distributed there (except for the Portuguese site where there is no record of fauna). This once again confirms that mountainous terrain and related prey may be more important to snow leopards than high altitude.

Another co-corresponding author of the paper, Wang Shiqi, a researcher at the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, believes that through comprehensive research in paleontology, molecular biology, finite element analysis, species distribution models and the use of big data, the research team revealed the evolutionary process of the snow leopard and concluded that "for snow leopards, mountainous terrain may be more important than climate itself." This conclusion can provide an important reference for the protection of snow leopards and is expected to become an example of how paleontological research results can serve the protection of rare living species.

Source: Beijing Youth Daily, China News Network