Fossil taxa used for specifying prior age distributions in the analyses.

Note that age assignments of the fossils follow the most recent accepted ages for the sediments in which the fossils have been found, not the ages given in the original reports. Following best practice guidelines [64], numerical ages assigned to different time periods correspond to their upper bounds as defined in The Geologic Time Scale 2012 [71]. Node numbers refer to those indicated in (Figs 1–4). 1 Minimum age is constrained by radiometric dating [83]. 2 Upper bound of the Poole Formation at the locality is 46 Myr [84]. 3 Bembridge Flora recently placed in the Late Eocene [85–87]. Fossil taxa used for specifying prior age distributions in the analyses.