Review: Implications of vertebrate fossils for paleo-elevations of the Tibetan Plateau

The uplift of the Tibetan Plateau is an important geological event, but there is considerable controversy about its growth history. Different geological observations contribute to this controversial issue, while data from geochemistry, tectonics, and paleontology further fuel the debate. Vertebrate fossils have provided significant evidence for documenting the uplift of the Tibetan Plateau in the geologic past. The earliest fossil evidence recently collected from the Oligocene Dingqing Formation in central Tibet includes the climbing perch and cyprinine fish fossils whose modern close relatives are distributed in the tropical zone of Asia and Africa. These discoveries not only are significant for the phylogeny and zoogeography of fishes, but also imply that the hinterland of the Tibetan Plateau was a warm and humid lowland at ~26 Ma. The co-existing plant assemblage, which includes palms and golden rain trees among others, indicates that the warm and humid airs from the Indian Ocean could flow deeply into central Tibet, consistent with the inference from the fish fossils. Since that time, the geographical features and natural environments within the Tibetan Plateau have greatly changed. The Tibetan Plateau was consistently uplifted in the Early Miocene and reached an elevation of ~3000 m, which was demonstrated by fish, mammal, and plant fossils. The endemic schizothoracines (snow carps) originated from the Miocene when the Tibetan Plateau turned into a barrier for mammalian migrations between north and south sides. A series of fish and mammal fossils provided unequivocal evidence that the Tibetan Plateau uplifted close to its modern elevation in the Pliocene and developed a cryospheric environment. As a result, the plateau region became the origination center for the cold-adapted Quaternary Ice Age fauna. •There have been heated debates about the history and process, especially paleo-elevations of Tibetan Plateau uplift.•Paleo-elevations of northern Tibet were lower than 2000 m during the Oligocene, too low to hinder the migration of mammals.•Until the Miocene, the plateau’s elevation reached about 3000 m, which became an obstacle for the exchange of large mammals.•In the Pliocene, the plateau reached its modern elevations of >4000 m, causing a cryospheric environment of the Ice Age fauna.•Paleontologists failed to search ancestors of the Ice Age fauna in the Pliocene and Quaternary Arctic tundra and steppe.•Cold environments forced the ancestors of the I