Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods^1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome^3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins^5–7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes⁸. This 15-fold increase in genus-level sampling relative to comparable nuclear studies⁹ provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.

Recent molecular phylogenetic studies in Chrysobalanaceae as well as new analyses presented in this study cast doubt on the monophyly of the three largest genera in the family, Couepia, Hirtella and Licania. Couepia, a Neotropical genus, had species appearing in four separate clades, the majority of species sequenced, however, form a highly supported clade, referred to here as core Couepia (including the type species). These results lend support to a revised taxonomy of the genus, and to resolve Couepia as monophyletic the following taxonomic changes are here proposed: Couepia recurva should be transferred to Hirtella, C. platycalyx transferred to Licania, C. longipendula and C. dolichopoda transferred to Acioa, and a new genus, Gaulettia, is proposed to accommodate species of the Gaulettia clade and allies.