Biogeography and early diversification of Tapinotaspidini oil-bees support presence of Paleocene savannas in South America.

•Tapinotaspidini broad phylogeny indicates monophyly of most genera.•Tapinotaspidini bees originated in Cerrado-like savannas in the Paleocene.•Transitions to forested areas slightly increase speciation rates.•Malpighiaceae is the ancestral host for floral oils.•Shifts to other oil plant families are possibly linked to habitat shifts.