Genomes, fossils, and the concurrent rise of modern birds and flowering plants in the Late Cretaceous

Despite modern DNA advances, scientists still know little about how and when early bird groups evolved. Using new approaches to mine genomic information among 124 species covering most of modern bird diversity, we found that the main lineages of birds first divided into two groups: one mostly land-based and the other containing water-associated species. We demonstrate that modern birds date back further than previously assumed, much earlier than the dinosaurian extinction event, which seems to have had a limited impact on birds' evolution. Instead, a warming event around ~55 Mya appears to have triggered the diversification of modern seabirds. Our study indicates that the radiation of modern birds was in remarkable lockstep with that of flowering plants and other organisms.