biostudies-literatureUnknown6(5)Osozawa SAngiospermae radiation is widely recognized as a mid-Cretaceous event, but the adaptive radiation of <i>Asarum</i> and <i>Viola</i> as spring ephemerals also occurred during the Quaternary. To better understand the evolution of Angiospermae through geological time, a robust and well-calibrated timetree for Spermatophyta was constructed. The Angiospermae topology was aligned with the APG (Angiosperm Phylogeny Group) system, although node dates tend to be overestimated in recent mega-trees compared to those in this study. An exponential increase in the base substitution rate in recent geologic time was also revealed through the use of an alternative dating function in BEAST (Bayesian Evolutionary Analysis Sampling Trees) v1.10.4, followed by a presumed increase in the mid-Cretaceous. These ePlant-environment interactions (Hoboken, N.J.)e70084https://www.ebi.ac.uk/biostudies/studies/S-EPMC12444776biostudies-literatureSpermatophyta Molecular Clock: Time Drift and Recent Acceleration.PMC12444776Osozawa SfalseSpermatophyta Molecular Clock: Time Drift and Recent Acceleration.Angiospermae radiation is widely recognized as a mid-Cretaceous event, but the adaptive radiation of <i>Asarum</i> and <i>Viola</i> as spring ephemerals also occurred during the Quaternary. To better understand the evolution of Angiospermae through geological time, a robust and well-calibrated timetree for Spermatophyta was constructed. The Angiospermae topology was aligned with the APG (Angiosperm Phylogeny Group) system, although node dates tend to be overestimated in recent mega-trees compared to those in this study. An exponential increase in the base substitution rate in recent geologic time was also revealed through the use of an alternative dating function in BEAST (Bayesian Evolutionary Analysis Sampling Trees) v1.10.4, followed by a presumed increase in the mid-Cretaceous. These e2025-01-01T00:00:00Z2025 Oct2026-06-03T15:32:09.169Z2026-06-01T03:06:07.085ZS-EPMC124447764097809010.1002/pei3.70084