An early burst of skeletal evolution at the origin of dinosaurs

Abstract Over 230 million years of Earth’s history, dinosaurs became a major terrestrial animal clade and produced one of the most species-rich living tetrapod lineages: birds. Yet, largely because of uncertainty surrounding the phylogeny of early dinosaurs, the tempo and mode of their emergence and initial radiation remain poorly constrained. Here, we reconstruct the initial diversification of dinosaurs through Bayesian tip-dating analyses. Using nine morphological datasets, we estimate that di