The rhinoceros rhinoceros, which is closely related to the living rhinoceros, lived in the early to middle Miocene about 21.5 million to 12 million years ago, and has only been found in Western Europe and South Asia in the past.
According to the news from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, the research team of Deng Tao of the Institute has recently made an important breakthrough in the study of the rhinoceros rhinoceros, and they found a new rhinoceros fossil material in the middle Miocene in the concentric area of Ningxia.
Ecological restoration map of the mid-Miocene Yeptia rhinoceros in the Tongxin area of Ningxia. Institute of Paleospine, Chinese Academy of Sciences/Courtesy photo
The discovery and research results of rhinoceros fossils were recently published in the international professional academic journal Zoological Journal of the Linnean Society. The research team conducted phylogenetic analyses of distal rhinos such as rhinoceros and other true rhino groups, and explored the paleoecology of rhinoceros.
Researcher Deng Tao, the corresponding author of the paper, said that the first discovery of the fossil of the rhinoceros in East Asia not only enriches the biodiversity of the far-horned rhinoceros in Eurasia, expands the paleogeographic distribution range of the rhinoceros rhinoceros, but also provides important fossil evidence for the migration of the rhinoceros to East Asia. The results of phylogenetic analysis showed that the members of the rhinoceros formed a stable monophyletic clade, and the rhinoceros was a more advanced species in the genus Rhinoceros.
A positive specimen of a fossilized rhinoceros skull of the Leaf rhinoceros. Institute of Paleospine, Chinese Academy of Sciences/Courtesy photo
Deng Tao pointed out that the discovery of the fossil of the Ye's rhinoceros proves that the paleogeographic distribution of the rhinoceros is wide, stretching from Europe to southern Pakistan and China in Asia. Therefore, the migration of the rhinoceros in Eurasia was not hindered by ecological and geographical obstacles, and the climate of the Miocene also provided favorable conditions for the spread of the rhinoceros to East Asia, which preferred a warm and humid environment.
Sun Danhui, the first author of the paper and a postdoctoral fellow at the University of Chinese Academy of Sciences, said that the fossil material of Ye's rhinoceros found this time is a well-preserved adult skull, only the premaxillary part is missing, the dorsal side of the skull is concave, the nasal bone is thick and upturned, and the edges on both sides are drooping; the end of the nasal bone is thickened and rough, indicating the presence of a nasal horn; the posterior end of the nasal notch is located at the middle level of the upper third premolar; the anterior edge of the orbit is located at the level of the leading edge of the first molar; the premolar teeth are semimolarized, and the chalky development on the lateral side of the buccal teeth.
Reconstruction of the head of the rhinoceros (Guo Xiaocong/drawing). Institute of Paleospine, Chinese Academy of Sciences/Courtesy photo
She said that the rhinoceros is a smaller, distal rhinoceros, similar in size to the Sumatran rhino, with a height of about 1.3 meters at the shoulder and a body length of about 2.9 meters when standing, but with short limbs and a belly closer to the ground, it has a semi-aquatic lifestyle similar to that of a hippopotamus, which has a strong ecological indicative significance. It has a forward sloped occipital part and a low crown height, so it is speculated that the rhinoceros is mainly leaf-eating. In addition, pollen analysis in the concentric area showed that the overall vegetation was dominated by herbaceous Artemisia annua, and coniferous and broad-leaved forest components began to appear in the middle Miocene, and the appearance of these plant components provided a diversified food source for the Rhinoceros sylvestris.
At present, the earliest known rhinoceros appeared in Pakistan in South Asia, in the early Miocene between 21.5 million and 20 million years ago, and in Europe, small distal horned rhinoceros began to appear after 20 million years ago.
Results of phylogenetic analysis of the family Rhinoceidae. Institute of Paleospine, Chinese Academy of Sciences/Courtesy photo
It is known that rhinos, which have evolved for more than 50 million years, are the largest group of odd hoofs and have the highest ecological diversity – from the hot equator to the cold polar regions, rhinos have lived in different ways. However, the five species of rhinoceros, including the white rhinoceros, the black rhino, the Indian rhinoceros, the Javanese rhinoceros and the Sumatran rhinoceros, are all in an endangered state, and they all belong to the true rhino family, and together with the extinct tapir rhinoceros, running rhinoididae, amphibian rhinoceros and giant rhinoidae, they form the rhino superfamily.
According to China News Network