Chronogram obtained with BEAST using fossil and biogeographic calibration points. Chronogram obtained under partition scheme P3 (by genes, and protein coding genes 1st + 2nd position vs. 3rd position), Yule speciation tree prior model, and lognormal uncorrelated relaxed clock. The x-axis scale is in million years. Bars indicate 95% HPD intervals. Filled circles indicate fossil constraints and open circles indicate biogeographic constraints (see Material and Methods for details). The geological time scale and the main geological events that occurred during the opening of the western Mediterranean Basin are indicated below the x-axis. Photograph of a Parachtes vernae male (photo credits E. Mateos).