Did the end-Cretaceous mass extinction event, by eliminating non-avian dinosaurs and most
of the existing fauna, trigger the evolutionary radiation of present-day mammals? Here we
construct, date and analyse a species-level phylogeny of nearly all extant Mammalia to bring
a new perspective to this question. Our analyses of how extant lineages accumulated
through time show that net per-lineage diversification rates barely changed across the
Cretaceous/Tertiary boundary. Instead, these rates spiked significantly with the origins of the …