Age estimates of evolutionary divergence events within Dreissenidae. Maximum clade credibility chronogram based on BEAST analysis (lognormal clock model) of concatenated sequences of four genes (18S, 28S and 16S rRNA and COI). Mean divergence ages are shown above the nodes and 95% highest posterior density intervals (95% HPD ) are given in parentheses below nodes and denoted by blue horizontal bars. Major geological periods are indicated in million years on the time scale bellow the tree. Bayesian posterior probabilities were 1.0 for all nodes except for Mytilopsis + Congeria node (0.99) and C. jalzici + C. mulaomerovici node (0.99).