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Holding particular biological resources, the Tibetan Plateau is a unique geologic-geographic-biotic interactively unite and hence play an important role in the global biodiversity domain. The Tibetan Plateau has undergone vigorous environmental changes since the Cenozoic, and played roles switching from "a paradise of tropical animals and plants" to "the cradle of Ice Age mammalian fauna". Recent significant paleontological discoveries have refined a big picture of the evolutionary history of biodiversity on that plateau against the backdrop of major environmental changes, and paved the way for the assessment of its far-reaching impact upon the biota around the plateau and even in more remote regions. Here, based on the newly reported fossils from the Tibetan Plateau which include diverse animals and plants, we present a general review of the changing biodiversity on the Tibetan Plateau and its influence in a global scale. We define the Tibetan Plateau as a junction station of the history of modern biodiversity, whose performance can be categorized in the following three patterns: (1) Local origination of endemism; (2) Local origination and "Out of Tibet"; (3) Intercontinental dispersal via Tibet. The first pattern is exemplified by the snow carps, the major component of the freshwater fish fauna on the plateau, whose temporal distribution pattern of the fossil schizothoracines approximately mirrors the spatial distribution pattern of their living counterparts. Through ascent with modification, their history reflects the biological responses to the stepwise uplift of the Tibetan Plateau. The second pattern is represented by the dispersal history of some mammals since the Pliocene and some plants. The ancestors of some Ice Age mammals, e.g., the wholly rhino, Arctic fox, and argali sheep first originated and evolved in the uplifted and frozen Tibet during the Pliocene, and then migrated toward the Arctic regions or even the North American continent at beginning of the Ice Age; the ancestor of pantherines (big cats) first rose in Tibetan Plateau during the Pliocene, followed by the disperse of its descendants to other parts of Asia, Africa, North and South America to play as top predators of the local ecosystems. The early members of some plants, e.g., Elaeagnaceae appeared in Tibet during the Late Eocene and then dispersed and were widely distributed to other regions. The last pattern is typified by the history of the tree of heaven (Ailanthus) and climbing perch. Ailanthus originated in the Indian subcontinent, then colonized into Tibet after the Indian-Asian plate collision, and dispersed therefrom to East Asia, Europe and even North America. The climbing perches among freshwater fishes probably rose in Southeast Asia during the Middle Eocene, dispersed to Tibet and then migrated into Africa via the docked India. These cases highlight the role of Tibet, which was involved in the continental collision, in the intercontinental biotic interchanges. The three evolutionary patterns above reflect both the history of biodiversity on the plateau and the biological and environmental effects of tectonic uplift. [ABSTRACT FROM AUTHOR]

The remarkable uplift of the Tibetan Plateau in the Neogene had great impacts on the climate and environment of East Asia and even the world. Therefore, establishment of the Neogene stratigraphic framework of the Tibetan Plateau is of great significance to research in various fields of geosciences. Based on marine sediments, the international chronostratigraphic system of the Neogene is divided into six stages in the Miocene and two stages in the Pliocene. Since the beginning of the Cenozoic, the share of terrestrial strata on continents has increased rapidly. By the Neogene, it had far exceeded that of marine strata, and almost all deposits on the Tibetan Plateau and its surrounding areas were terrestrial strata. In China, the Miocene includes five stages and the Pliocene includes two stages. Except for the Tunggurian of the Miocene, which has a lower boundary at 15 Ma, the other stages have the same paleomagnetic definitions and time intervals as the corresponding international marine stages. Mammalian fossils play a very important role in the division and correlation of Cenozoic terrestrial strata, and rodent, carnivore, proboscidean, perissodactyl and artiodactyl fossils are especially important in Neogene terrestrial biostratigraphy. There are many basins with well-exposed strata and abundant mammalian fossils in the Tibetan Plateau. The lower boundary stratotype sections of the Neogene Xiejian and Bahean stages are located respectively in the Xining and Linxia basins, and there are precise paleomagnetic dates in coordination with mammalian fossils. The lower boundary stratotypes of other stages can also be effectively determined in the Tibetan Plateau. Many first appearing mammalian genera in East Asia also appeared in the Tibetan Plateau and its surrounding areas, especially in the Linxia Basin on the northeast margin and in the Siwaliks on the southwest margin. Among them, Prodeinotherium first appeared at the bottom of the Miocene in the Siwaliks, and the earliest Hipparion of the Old World first appeared at the bottom of the Bahean Stage in the Linxia Basin. Carbon and oxygen isotope analysis of enamel and paleosols of Cenozoic sediments and mammal fossils in the Tibetan Plateau and its surrounding areas have been used to reconstruct the climate, environment and vegetation development characteristics, and revealed that these changes were not only related to global change, but also had regional features. Evidence of the Late Miocene C4 plant expansion event based on carbon isotope changes comes from the southern margin of the Tibetan Plateau, but in sharp contrast, δ13C indicates that there was still no clear or significant C4 plant signal on the northern margin of the Tibetan Plateau until the end of the Neogene. The δ18O analysis shows that there were several major climate change events in the Cenozoic, especially in the Late Miocene at about 7 Ma, when positive drift of δ18O indicates that the northern and southern sides of the Tibetan Plateau were changing to drier environments. The strong uplift of the Tibetan Plateau in the Late Miocene strengthened the thermal contrast between sea and land, which strengthened monsoon circulation and led to the expansion of C4 vegetation in South Asia. However, the East Asian summer monsoon, which can bring atmospheric precipitation and a climate suitable for C4 plants to northern China, was not enough to affect the northern Tibetan Plateau. The Tibetan Plateau on the whole rose to an altitude of about 3000 m in the Miocene, becoming a barrier to mammalian migration; it reached its modern altitude of more than 4000 m in the Pliocene, thus forming a cryosphere environment, which led to the emergence of ancestral types of the Ice Age fauna. [ABSTRACT FROM AUTHOR]

This paper describes a plant megafossil assemblage from the Pliocene strata of Xiangzi, Zanda Basin in the western Qinghai-Tibet Plateau. Twenty-one species belonging to 12 genera and 10 families were identified. Studies show that the Pliocene vegetation in Zanda Basin was mostly deciduous shrub composed of Cotoneaster, Spiraea, Caragana, Hippophae, Rhododendron, Potentilla fruticosa, etc. Leaf sizes of these taxa were generally small. Paleoclimate reconstruction using Coexistence Analysis and CLAMP showed that this area had higher temperature and precipitation in the Pliocene than today, and distinct seasonal precipitation variability was established. The reconstructed paleoelevation of Zanda Basin in the Pliocene was similar to modern times. In the context of central Asian aridification, the gradual drought in the area beginning in the late Cenozoic caused vegetation to transition from shrub to desert, and the flora composition also changed. [ABSTRACT FROM AUTHOR]