Ficus leaves within the Ficus subgenus Urostigma (Moraceae) from the middle Miocene in South China and their biogeography implications

Ficus L. (Moraceae) is a ubiquitously diverse genus in lowland rainforests and has a worldwide distribution in a variety of habitats. It provides an excellent system for historical biogeographic analyses. We describe three fossil leaves with diagnostic features within the subgenus Urostigma of Ficus, namely, Ficus fujianensis sp. nov., F. zhangpuensis sp. nov., and Ficus sp. in lacustrine sediments from the middle Miocene of Fujian, South China. These species are erected based on the association of venation type and margin vein with cuticle remains. These findings greatly expand the known spatial biogeography distribution of the genus Ficus in geological history. We propose a potential route for the dispersal of Indian and South China organisms and highlight the important role of the Tibetan region in the migration of tropical rainforest biota between India and South China during the Paleogene based on fossil records. In addition, our fossil data reveal a thriving Ficus subgenus Urostigma in southeast China and indicate that a complex subgenus diversification of Ficus occurred in South China at least in the Miocene, combined with fossil records from the Oligocene Wenshan flora. ?? 2022 Published by Elsevier B.V.