| Abstract |
The genus Bauhinia Plumier ex Linnaeus s.l. (Fabaceae) includes c. 380 species of trees, shrubs, lianas and herbs, distributed in pantropical regions and with previous fossil records from the late Paleocene to the Pliocene, mainly recovered from Asia. Here we report the earliest fossil record of Bauhinia s.l., in the form of a naturally folded leaf from the middle Paleocene of the Sanshui Basin, Guangdong, South China. Based on detailed morphological comparisons, the fossil is named Bauhinia sanshuiensis sp. nov. Its discovery indicates that Bauhinia s.l. had already appeared in its modern diversity centre at least by the middle Paleocene. The results of Biomod2 species distribution modelling quantitatively support the significance of the Kohistan–Ladakh Island Arc in facilitating the floristic exchange of Bauhinia s.l. between Africa and Asia. The diversification and modernization of Bauhinia s.l. in China are discussed in detail based on substantial fossil evidence, underscoring China's crucial role in the phytogeographic history of this genus. Nearest relative analysis for Bauhinia sanshuiensis suggests that it may have been a vine or shrub, adapted to temperatures similar to those of modern Sanshui, but with less precipitation.
|
