Yang Tao, Cai Jia-Hao, Dai Yan-Zhi, Chen Hong-Yu, Han Lei, Zhang Li, Liang Wei-Yu, Li Xu-Jun, Li Wen-Jia, Wu Jing-Yu, Xie San-Ping, Yan De-Fei
School of Earth Sciences and Key Laboratory of Mineral Resources in Western China (Gansu Province), Lanzhou University, Lanzhou 730000, China.
Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
Plant Divers. 2023 Mar 30;46(1):101-115. doi: 10.1016/j.pld.2023.03.007. eCollection 2024 Jan.
Understanding the paleoenvironment and phytogeographical history of the Tibetan Plateau, China relies on discovering new plant fossils. The Qaidam Basin has long been regarded as an ideal 'field laboratory' to investigate the paleoclimate and paleobiological evolution of the northern Tibetan Plateau. However, fossil angiosperms from the Qaidam Basin are rare, and our knowledge of its paleovegetation is poor. Here, we report fossil leaves and fruits of Betulaceae found from the Oligocene Shangganchaigou Formation of northwestern Qaidam Basin (Huatugou area). Comparative morphological analysis led us to assign the fruits to the subgenus and the leaves to . These findings, together with other reported fossil plants from the same locality, reveal a close floristic linkage between the Qaidam Basin and Europe during the Oligocene. The northern pathway of this floristic exchange may have crossed through the Qaidam Basin during the late Paleogene. This floristic linkage may have been facilitated by the continuous narrowing of the Turgai Strait and stronger westerlies, which transported moisture and provided favorable climatic conditions. Indeed, fossil plants collected from the Qaidam Basin suggest that during the Oligocene this region had warm and humid deciduous broad-leaf forest, which differs from the region's modern vegetation and indicates that the Qaidam Basin may have been a suitable region for these plants to flourish and spread during the Oligocene.
了解中国青藏高原的古环境和植物地理历史依赖于发现新的植物化石。长期以来，柴达木盆地一直被视为研究青藏高原北部古气候和古生物演化的理想“野外实验室”。然而，柴达木盆地的被子植物化石稀少，我们对其古植被的了解也很匮乏。在此，我们报道了在柴达木盆地西北部（花土沟地区）渐新世的上干柴沟组发现的桦木科植物的叶子和果实化石。通过比较形态学分析，我们将果实归入 亚属，将叶子归入 。这些发现，连同同一地点报道的其他化石植物，揭示了渐新世期间柴达木盆地与欧洲之间密切的植物区系联系。这种植物区系交流的北方路径可能在古近纪晚期穿过柴达木盆地。图尔盖海峡的持续变窄和更强的西风可能促进了这种植物区系联系，西风输送了水分并提供了有利的气候条件。事实上，从柴达木盆地采集的化石植物表明，渐新世期间该地区有温暖湿润的落叶阔叶林，这与该地区现代植被不同，表明渐新世期间柴达木盆地可能是这些植物繁荣和扩散的适宜地区。
