Chinanews.com, Beijing, February 10th (Reporter Sun Zifa) How did rhinos on the earth evolve and spread "with a heart" before the appearance of human beings millions of years ago?
Deng Tao's research team from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences (Institute of Paleontology, Chinese Academy of Sciences) has completed the most complete Late Cenozoic (26.5 million years ago) in Eurasia and the world through the latest research on the abundant rhinoceros fossils in Linxia Basin, Gansu -2.55 million years) rhinoceros continuous evolution sequence, among which, the living African black rhinoceros and the extinct Iranian rhinoceros have found their ancestor type fossils in the Linxia Basin.
Researcher Deng Tao introduced the latest research results of rhino fossils in Linxia Basin, Gansu.
Photo by China News Agency reporter Sun Zifa
This important paper on the discovery of paleontological fossils was recently published in the international professional academic journal Palaeogeography, Palaeoclimatology, Palaeoecology, proving that the Linxia Basin has very continuous and abundant rhinoceros fossils in Eurasia The distribution is not only an important material for studying the evolution of rhinoceros, but also a good indicator for dividing and comparing key signs of strata and judging the climate and environmental background.
Two eras of fauna rhino dominance
Researcher Deng Tao, the first author and corresponding author of the paper, said in an exclusive interview with a reporter from China News Agency that rhinoceros fossils are an important part of the Late Cenozoic mammal fauna in Linxia Basin, Gansu Province, and rhinoceros dominated fauna in two eras, namely The giant rhinoceros of the late Oligocene (27.82 million years ago-23.03 million years ago) and the large-lipped rhinoceros of the late Miocene (11.63 million years ago-5.33 million years ago).
In the Late Oligocene fauna of the Linxia Basin, among the 12 species of large mammals, members of the family Rhinoceridae accounted for 9 species, including the genera and species of Rhinocerosidae, Macrorhinoidae and Eurhinoceridae. It is characterized by the first appearance of Giant Rhinoceros and Yagou Turpan Giant Rhino and the last appearance of Horgos Junggar Giant Rhino.
After the end of the Oligocene (33.9 million years ago-23.03 million years ago), both the running rhinoceros and the giant rhinoceros disappeared in the Linxia Basin, and there were only true rhinoceros in the strata of the Early Miocene (23.03 million years ago-15.97 million years ago) Lanzhou giant rhinoceros.
Ecological restoration map of the Iranian rhinoceros in the Linxia Basin during the Late Miocene.
Photo by Chen Yu
He pointed out that due to the high diversity, wide geographical distribution and rapid evolution of rhinos, rhinoceros fossils have become good biomarkers for stratigraphic division and can be compared across continents.
Madrid Spanish rhinoceros and Laogou odd-horned rhinoceros were found in the middle Miocene (15.97 million years ago-11.63 million years ago) strata of the Linxia Basin. Their body structure reflects that they lived in a forest environment. In-depth comparison shows that the population migrated along the route on the northern side of the Qinghai-Tibet Plateau; unlike the situation in North America and Europe where the three-toed horse was the dominant group in the Late Miocene, the Linxia Basin had the most abundant rhinoceros during this period.
African black rhino and Iranian rhino originated in China
Deng Tao said that the Late Miocene mammals in the Linxia Basin can be divided into four layers, and each layer has different rhinoceros fossils as a sign of division and comparison:
One is that in the Guonigou fauna, the most primitive rhinoceros rhinoceros and the huge rhinoceros (including simple rhinoceros, Linxia paradont, and broad-nosed Ningxia) belong to the late Miocene bottom world. key sign.
The second is that the Great Deep Groove Fauna has many fossil locations. Rhinoceros in each location is the group with the most abundant individuals, especially the Vickers rhinoceros, the Hezheng rhinoceros and the Iranian rhinoceros. and Gansu black rhino.
Thirdly, many sites in the Yangjiashan fauna show that Rhinoceros victoria and Hezheng rhinoceros continued to flourish, and Rhinoceros sinensis Lashmiri appeared for the first time.
Fourth, in the Qingpushan fauna in the southern part of the Linxia Basin, the Rhinoceros rhinoceros and Lin's Shanxi rhinoceros, and the rhinoceros Lin's rhinoceros in the subfamily Rhinoceros subfamily, were produced.
Deng Tao emphasized that the most important results are the Iranian rhinoceros and Gansu black rhinoceros found in the fauna of the Great Deep Trench. The team's in-depth research shows that although the Iranian rhinoceros has become extinct, the Iranian rhinoceros in the Linxia Basin lived about 900 years ago. Ten thousand years ago, it was 2 million years earlier than the 7 million-year-old Iranian rhino that was first discovered in Iran by paleontology and named after its territory according to convention. The relationship between the origin and evolution of the two is very clear; ancestral taxa.
The discovery and research of these two rhino fossils in the Linxia Basin prove that the Iranian rhinoceros and black rhinoceros first originated in China, and then they migrated westward and spread to Iran, Africa and other places. The Iranian rhinoceros became extinct about 7 million years ago, while the black rhinoceros The evolution in Africa continues to this day.
Late Miocene Gansu black rhino restoration map in Linxia Basin.
Photo by Chen Yu
Reflecting the huge impact of the uplift of the Qinghai-Tibet Plateau
Mammals are very sensitive to changes in climate and environment, and rhinoceros, as ungulates, is one of the effective indicators of paleoecology in the Linxia Basin.
The diversity of rhino heights in the Linxia Basin not only reflects changes in climate and other ecological and environmental indicators, but also reflects the huge impact of the uplift of the Qinghai-Tibet Plateau.
Deng Tao said that the Linxia giant rhinoceros is the descendant of the Bugti giant rhinoceros on the southern edge of the Qinghai-Tibet Plateau, which implies that there was still a channel for the exchange of animals between the north and the south on the Qinghai-Tibet Plateau during this period; The existence of the Pliocene reflected that there were widely distributed water bodies at that time; the Middle Miocene forests where the Spanish rhinoceros and the odd-horned rhinoceros lived were more lush and the water bodies were more abundant; major climate and environmental changes occurred at the turn of the middle and late Miocene, and a large number of rhinoceros rhinoceros The Late Miocene, when the rhinoceros and the greater lipped rhinoceros flourished, was a hot and semi-arid savannah, and the seasonal changes were strengthened. The Linxia Basin became a sanctuary for rhinos in East Asia; a large number of rhinoceros became extinct at the end of the Miocene, and they could eat high-fiber herbaceous plants The Shanxi rhinoceros lasted until the Pliocene; the Early Pleistocene, when the woolly rhinoceros spread from the Qinghai-Tibet Plateau, had a cold and dry climate, accompanied by a significant increase in altitude, and the environment was a relatively monotonous dry and cold grassland.
In addition, due to the strong competition of ruminants, the number of rhinoceros in the morning Pleistocene (5.33 million years ago-3.6 million years ago) and early Pleistocene (2.58 million years ago-770 thousand years ago) fauna decreased significantly, and the morning Pleistocene only Shanxi rhinoceros survived, and only one woolly rhinoceros existed in the early Pleistocene.
As an intermediate transitional type, the Nihewan woolly rhino species in the Linxia Basin connects the Pliocene species in the Zanda Basin on the Qinghai-Tibet Plateau and the Pleistocene species in the Nihewan Basin in the North China Plain.
A representative rhinoceros skull from the Linxia Basin.
Photo courtesy of Deng Tao
He believes that, in general, the evolution of rhinos was driven by the gradual expansion of open environments, especially reflected in the specialization of their feeding organs, such as teeth and snouts.
The Linxia Basin is a favorable area for revealing the relationship between the evolution of rhinoceros and its relationship with climate and environment changes in the Late Cenozoic, and it proves that rhinoceros fossils are of great significance in biostratigraphy.
Rhinos have a history of more than 50 million years of evolution
What kind of animal is a rhino?
Deng Tao said that the rhinoceros has an evolutionary history of more than 50 million years. It is the largest group in Perissodactyla and has the highest ecological diversity. From the hot equator to the cold polar regions, there have been different species. Rhinos live freely.
Although extant rhinos are odd-toed ungulates with relatively limited numbers and species, rhinos were an unusually prosperous group during most of the Cenozoic Era, adapting and radiating numerous branches in different ecological environments.
After horses, rhinos are the most successful group of perissodactyls on Earth.
Since the Oligocene, most terrestrial ecosystems in the northern hemisphere have one or more rhinos as part of the fauna, and the number of fossil genera and species of rhinos far exceeds that of horses, tapirs, and clawed animals that are also odd-toed animals and Ultralisk.
Deng Tao said that in Eurasia, Africa and North America, existing fossil research shows that rhinoceros existed in large numbers in the Cenozoic Era. In some fossil sites, their number of individuals is even more than that of all other mammals combined.
In terms of size, rhinos are often among the largest herbivorous mammals in most Cenozoic fauna.
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