Integrating palaeontological and molecular data uncovers multiple ancient and recent dispersals in the pantropical Hamamelidaceae

Aim The integration of palaeontological and phylogenetic data can improve our understanding in the spatio-temporal evolutionary processes of living organisms. However, how best to use fossil data in divergence time estimation and ancestral range reconstruction remains challenging. Here, we integrated palaeontological and molecular data to investigate the historical biogeography of Hamamelidaceae, a pantropical angiosperm family with abundant fossils outside its present distribution. Location Global tropical/subtropical areas. Methods Using seven DNA regions (>7,500 bp) from plastid and nuclear genomes, we reconstructed a robust phylogenetic framework for Hamamelidaceae with the first complete genus-level sampling. We used the tip-dating method with the 22 fossils to estimate divergence times for the family, and inferred the ancestral range of lineages under the dispersal-extinction-cladogenesis model by incorporating the fossils. Results Our biogeographic analysis indicates that extant Hamamelidaceae most likely originated in tropical Asia during the mid-Cretaceous, and in the family 20 dispersals occurred during three major time intervals: the Upper Cretaceous (c. 93-69 Ma), Palaeocene-Eocene (c. 63-39 Ma) and late Oligocene (c. 27-23 Ma). Main conclusions Overland migrations through available land bridges and island chains may have been mainly responsible for hamamelidaceous range expansions during these three episodes. This study contributes to our knowledge on the assembly and evolution of angiosperm-dominated tropical and subtropical forests.