Table 1.
Inferred node age in million years ago (Ma) for the most recent common ancestors (MRCA) of the different PV clades and for the root of the tree. The rows of the PV crown groups are named accordingly (figure 1), otherwise the taxonomic host group is given. An asterisk indicates the presence of one exception within the clade of PVs infecting mammals, which is a python PV (discussed in the text). The differences between the ancestral node ages of the crown groups as well as the root are significant after performing a Kruskal–Wallis rank sum test (chi-sq. = 51993, d.f. = 5, p < 2.2 × 10−16) and a multiple comparison test after Kruskal–Wallis (electronic supplementary material, table S3). Although the inferred times and the posterior distributions for the ancestral Alpha–Omikron and Delta–Zeta as well as the Beta–Xi and Lambda–Mu clades are similar (electronic supplementary material, figure S3), the significant difference between these groups was confirmed by a Wilcoxon rank sum test (W = 57 451 000, p < 2.2 × 10 − 16 and W = 50 158 000, p < 2.2 × 1016, respectively).
| PV clade | MRCA age (Ma) | 95% HPD |
|---|---|---|
| root | 424 | 402–446 |
| amniotes | 184 | 161–208 |
| Aves/Testudines (grey) | 171 | 148–195 |
| mammals* | 121 | 112–132 |
| Lambda–Mu (yellow) | 95 | 90–100 |
| Beta–Xi (green) | 94 | 88–100 |
| Delta–Zeta (blue) | 84 | 79–90 |
| Alpha–Omikron (red) | 83 | 76–90 |
| Sirenia (black) | 77 | 68–87 |