Bayesian inference of global land plant diversification dynamics across the Phanerozoic

Abstract

Underlying diversification patterns and potential drivers of land plants remain puzzling, particularly at deep-time and global scales. Here, we reconstruct the diversification dynamics of land plants using an updated time-calibrated phylogeny comprising approximately 30,000 extant species, and nearly 40,000 fossil occurrences within the Bayesian birth-death frameworks. Our analyses indicate that angiosperms exhibit the highest diversification rates, whereas ferns underwent a marked diversification increase during the Cretaceous, coincident with the rapid radiation of angiosperms. Among the major Phanerozoic mass extinctions, the Cretaceous-Paleogene event has the most significant impact on land plant diversity, with estimated genus-level losses of 13%, 14%, and 4% in bryophytes, pteridophytes, and gymnosperms. We identify a pattern consistent with competitive displacement scenario, in which pteridophytes origination rates declined as gymnosperm diversity increased, accompanying the transition from pteridophyte- to gymnosperm-dominated floras. We find that plant-insect interactions have originated as early as the emergence of pteridophytes, potentially promoting the diversification of pteridophytes and gymnosperms. During the Cretaceous, these associations shifted toward angiosperms, as indicated by a positive relationship between insect diversity and angiosperm origination rates. Finally, continental fragmentation, fluctuations in aridity, atmospheric carbon and sedimentary dynamics, showed stronger associations with the successive rise and decline of major land plant groups.