Phylogeography and cryptic diversity of the solitary‐dwelling silvery mole‐rat, genus Heliophobius (family: Bathyergidae)

Alongside the eusocial naked mole‐rat, H eterocephalus glaber , H eliophobius argenteocinereus represents the second oldest lineage within the A frican mole‐rat family B athyergidae, and phylogenetically intermediate between the E ast A frican H et. glaber and the S outh A frican genera B athyergus and G eorychus . Across its geographic range, H el.. argenteocinereus is widely distributed on both sides of the E ast A frican R ift S ystem ( EARS ), and is a key taxon for understanding the phylogeographic patterns of divergence of the family as a whole. Phylogenetic analysis of 62 mitochondrial cyt b sequences, representing 48 distinct haplotypes from 26 geographic locations across the range of H eliophobius , consistently and robustly resolved six genetically divergent clades that we recognize as distinct evolutionary species. Early species descriptions of H eliophobius were synonymized into a monotypic taxonomy that recognized only H el. argentocinereus . These synonyms constitute available names for these rediscovered cryptic lineages, for which combined morphological and genetic evidence for topotypical populations endorses the recognition of six to eight distinct taxa. Bayesian estimates of divergence times using the fossil P roheliophobius as a calibration for the molecular clock suggest that the adaptive radiation of the genus began in the early M iocene, and that cladogenesis, represented in the extant species, reflects a strident signature of tectonic activity that forged the principal graben in the EARS .