Time-calibrated tree resulting from the partitioned Bayesian analysis of the combined dataset.
Age estimates correspond to the results of the BRC analysis using the fossil constraint with an exponential distribution. Labels on nodes correspond to the nodes listed in Table 2. Posterior probabilities (left) and bootstrap values (right) are also indicated for major nodes (values below<0.50 are not figured). On the bottom left (lower panel), a map is included to figure the localities of almost all sampled Arvicanthis niloticus specimens (with the exception of the specimen from Ethiopia and the two specimens from Egypt). Additional information on mountain and hydrogeographic formations of interest is also provided. A red line is also used to figure the distribution limits of the two distinct A. niloticus cytotypes (ANI-1a and ANI-1b; see text for details). On the right side, the general origin of Arvicanthis niloticus specimens is represented using circles filled with colours corresponding to those used on the map. In addition, vertical sidebars highlight the three major lineages (A, B and C) and the four major clades within the lineage C (C-1, C-2, C-3 and C-4). On the bottom left again (upper panel), the simplified phylogenetic topology of Arvicanthis studied here is represented with corresponding geographic origin of extant lineages as well as of MRCA as inferred by the ancestral area optimization under Mesquite (see text for details).