Our analysis suggests that in the late Eocene (~ 49 Mya) arboreal Sphaenorhynchus diverged from the ancestral scinaxines in the Atlantic Coastal Forest of Brazil. Our limited data suggest that the Brazilian and Amazonian clades of Sphaenorhynchus separated in the late Oligocene (~ 22 Mya). As the climate became drier and seasonal in southern South America in the early Oligocene (~ 34 Mya), the scinaxine stock diverged into Julianus in the southeastern part of the range, Ololygon in the Atlantic Coastal Forest, and Scinax in the Amazon Basin.