An ancient origin for the enigmatic Flat-Headed Frogs (Bombinatoridae: Barbourula) from the islands of Southeast Asia

Background: The complex history of Southeast Asian islands has long been of interest to biogeographers. Dispersal and
vicariance events in the Pleistocene have received the most attention, though recent studies suggest a potentially more
ancient history to components of the terrestrial fauna. Among this fauna is the enigmatic archaeobatrachian frog genus
Barbourula, which only occurs on the islands of Borneo and Palawan. We utilize this lineage to gain unique insight into the
temporal history of lineage diversification in Southeast Asian islands.
Methodology/Principal Findings: Using mitochondrial and nuclear genetic data, multiple fossil calibration points, and
likelihood and Bayesian methods, we estimate phylogenetic relationships and divergence times for Barbourula. We determine
the sensitivity of focal divergence times to specific calibration points by jackknife approach in which each calibration point is
excluded from analysis. We find that relevant divergence time estimat...