Unveiling the identity of Kerr's Atlantic tree rat, Phyllomys kerri (Rodentia, Echimyidae)

Arboreal spiny rats of the genus Phyllomys are the most diverse group of echimyid rodents in the Atlantic Forest. Many species of Phyllomys have small geographic ranges and are rare in scientific collections. One of them is Phyllomys kerri known from only three specimens collected in a single locality almost 80 year s ago. The identity and the taxonomic validity of this enigmatic species has been questioned in recent decades. Field surveys at different sites along the southeastern portion of the Atlantic Forest in Brazil recovered specimens of Phyllomys that we hypothesized to be P. kerri based on external similarities to the type specimen and proximity to its type locality. Here we obtained DNA sequences from these recently collected specimens and historic DNA from a topotype of P. kerri collected in 1941. Our results supported the status of P. kerri as a valid species and showed it is phylogenetically positioned among the southern clade of Phyllomys species. We therefore provide an emended diagnosis of P. kerri, comparing it with sympatric congeners, and provide comments on its evolutionary affinities, geographic distribution, and conservation status.