Figure 8

Divergence time tree inferred using the constrained topology. Divergence times inferred using the constrained tree in BEAST. Major crown clades are named, along with two extinct clades (Simoliophiidae and Madtsoiidae). The red line separating the Mesozoic and Cenozoic eras marks the Cretaceous-Paleogene (K-Pg) boundary at 66 Ma. Timescale is in millions of years. Circled numbers and green stars correspond to calibration dates outlined in Additional file 12. Colored boxes indicate major clades. Fossil taxa are marked with a dagger (†). Grayed taxa names indicate extant species that are included on the basis of phenotypic data only.