Figure 4.

Chronogram of the circumglobal seahorse clade. An ultrametric tree of the circumglobally distributed seahorse lineage scaled to geological time constructed using the program MULTIDIVTIME [57]. White circles indicate nodes that were used to calibrate the molecular clock; letters within these correspond to the ones used in Fig. 2. Time intervals used for calibration were: A: 3.1 – 4.6 mya; B: 3.0 – 4.0 mya; D: 11.2 – 20.5 mya. Grey bars indicate 95% confidence intervals of internal nodes.