title: Locomotive implication of a Pliocene three-toed horse skeleton from Tibet and its paleo-altimetry significance.
abstract: The Tibetan Plateau is the youngest and highest plateau on Earth, and its elevation reaches one-third of the height of the troposphere, with profound dynamic and thermal effects on atmospheric circulation and climate. The uplift of the Tibetan Plateau was an important factor of global climate change during the late Cenozoic and strongly influenced the development of the Asian monsoon system. However, there have been heated debates about the history and process of Tibetan Plateau uplift, especially the paleo-altimetry in different geological ages. Here we report a well-preserved skeleton of a 4.6 million-y-old three-toed horse (Hipparion zandaense) from the Zanda Basin, southwestern Tibet. Morphological features indicate that H. zandaense was a cursorial horse that lived in alpine steppe habitats. Because this open landscape would be situated above the timberline on the steep southern margin of the Tibetan Plateau, the elevation of the Zanda Basin at 4.6 Ma was estimated to be ∼4,000 m above sea level using an adjustment to the paleo-temperature in the middle Pliocene, as well as comparison with modern vegetation vertical zones. Thus, we conclude that the southwestern Tibetan Plateau achieved the present-day elevation in the mid-Pliocene.
authors.affiliation: Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China. dengtao@ivpp.ac.cn
authors.forename: Tao
authors.initials: T
authors.lastname: Deng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Zhijie Jack
authors.initials: ZJ
authors.lastname: Tseng
authors.forename: Gary T
authors.initials: GT
authors.lastname: Takeuchi
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Guangpu
authors.initials: G
authors.lastname: Xie
authors.forename: Shiqi
authors.initials: S
authors.lastname: Wang
authors.forename: Sukuan
authors.initials: S
authors.lastname: Hou
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001842:Bone and Bones / Q000033:anatomy & histology*; D002247:Carbon Isotopes / Q000032:analysis; D005269:Femur / Q000033:anatomy & histology; D005580:Fossils; D005843:Geography; D006736:Horses / Q000033:anatomy & histology* / Q000145:classification / Q000502:physiology; D050279:Metacarpal Bones / Q000033:anatomy & histology; D009043:Motor Activity; D010103:Oxygen Isotopes / Q000032:analysis; D010163:Paleontology; D012863:Skeleton; D018609:Tibet; D013977:Tibia / Q000033:anatomy & histology; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D010103:Oxygen Isotopes