Researchers examine how topography shaped ancient Tibet's biotic evolution. Due to sparse fossil records, the topography of ancient Tibet and its impact on the region's biodiversity are unclear. To better understand Tibet's ancient environment, Tao Su, Zhe-Kun Zhou, and colleagues analyzed fossils of 70 different plant taxa dating to approximately 47 million years ago. The authors excavated the fossils at an elevation of approximately 4,850 meters in central Tibet's Bangor Basin. During the middle Eocene, central Tibet exhibited an optimal ecosystem for diverse, subtropical vegetation. A heterogeneous, lowland forest in Tibet grew at an elevation of approximately 1,500 meters; this forest was not dominated by a specific species. Frost was rare, and precipitation was largely seasonal under a monsoonal climate. The region also experienced high humidity, short winters, and a mean annual temperature of approximately 19°C. Tibet's ancient flora did not resemble contemporaneous flora found in the Indian Plate, but rather contemporaneous flora from Germany and the United States. The findings suggest that an east-west running valley persisted for at least 25 million years in central Tibet before giving way to the present elevated plateau, which gradually formed via compression-driven landscape changes, according to the authors.
###
Article #20-12647: "A Middle Eocene lowland humid subtropical "Shangri-La" ecosystem in central Tibet," by Tao Su et al.
MEDIA CONTACT: Tao Su, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, CHINA; e-mail: <sutao@xtbg.org.cn>; Zhe-Kun Zhou, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, tel: +86-691-8716932; e-mail: <zhouzk@xtbg.ac.cn>
Journal
Proceedings of the National Academy of Sciences