Figure 1

Combined chronogram and biogeographic analysis of the paleotropical genus Lepisorus . The tree is obtained from the BEAST analysis, with branches proportional to absolute age (in millions of years) calculated from median branch length of 10,000 Bayesian trees. The tree was calibrated at the most basal node (Paragramma sister to the remaining lepisoroid ferns) with 19.6 Ma (based on Schuettpelz and Pryer, 2009; Schneider et al., 2010) as a log-normal distributed calibration, which is indicated with the sign “\\”. The well-resolved nine clades are indicated as I – IX (Wang et al. 2010a). Node charts show the relative probabilities of alternative ancestral distribution obtained by statistical dispersal-vicariance analysis (S-DIVA) optimization over the 10,000 Bayesian trees. Present ranges for each species are given after the species name and detailed information is given in Additional file 2: Table S1. Areas used in the biogeographic analysis: A, Africa; B, Tropical Asia; C, Japan; D, Taiwan; E, Southwest China; F, Hainan; G, most northern part of China; H, most southern part of China. The color gradients shown in the top left corner correspond to the regions. The red arrow represents the “maximum shift point”. The black shaded boxes under the time scale correspond to the flux phases of East Asian monsoon.