The fact that a relaxed lognormal molecular clock fits best to our data was consistent with an estimated coefficient of variation of 0.29 and 0.41 (respectively, for dataset comprising P1 and VP1 regions) that reflected significant rate heterogeneity, thus rejecting a strict molecular clock. The resulting trees for each run were summarized using Tree-Annotator and the maximum clade credibility tree was visualized with FigTree v1.1.2 [34] . BEAST xml files are available as additional files 2, 3, 4 and 5.