The diversification of extant flowering plants was delayed for 37–56 million years after the origin of families, with an average longer delay in tropical ecosystems than in arid and temperate ecosystems.
The Early Cretaceous (145–100 million years ago (Ma)) witnessed the rise of flowering plants (angiosperms), which ultimately lead to profound changes in terrestrial plant communities. However, palaeobotanical evidence shows that the transition to widespread angiosperm-dominated biomes was delayed until the Palaeocene (66–56 Ma). Important aspects of the timing and geographical setting of angiosperm diversification during this period, and the groups involved, remain uncertain. Here we address these aspects by constructing and dating a new and complete family-level phylogeny, which we integrate with 16 million geographic occurrence records for angiosperms on a global scale. We show substantial time lags (mean, 37–56 Myr) between the origin of families (stem age) and the diversification leading to extant species (crown ages) across the entire angiosperm tree of life. In turn, our results show that families with the shortest lags are overrepresented in temperate and arid biomes compared with tropical biomes. Our results imply that the diversification and ecological expansion of extant angiosperms was geographically heterogeneous and occurred long after most of their phylogenetic diversity originated during the Cretaceous Terrestrial Revolution.
Dr Santiago Ramírez Barahona from Universidad Nacional Autónoma de México will present his work in an online seminar on Tuesday, 10 November 2020, at 11.00 (Australian Eastern Daylight Time).
For details of access to this e-seminar or more information about our seminars and future announcements, please contact Hervé Sauquet.