New data on the rare <i>Oxymycterus itapeby</i> and the Anajatuba hantavirus host <i>Oligoryzomys mattogrossae</i> (Rodentia: Cricetidae): the importance of surveys in challenging-to-access environments in the Brazilian Cerrado

A recent survey of small nonvolant mammals conducted in a protected area of central Brazil that has been studied for a long time has, for the first time, recorded the rare cricetid species Oxymycterus itapeby in the core Cerrado. Until now, this Data Deficient species was known solely from 11 specimens from southern Brazil, three of them being tissue samples only. The karyotype and the gross stomach morphology of the species are described for the first time. The Anajatuba hantavirus host, the pygmy rice rat Oligoryzomys mattogrossae, was also collected and analysed in a phylogeographic context, revealing a geographic structuring related to two main hydrographic basins of Cerrado. All specimens collected during the study were identified based on morphological characters and molecular data (mt-Cytb). The present records were obtained from specimens sampled in a habitat frequently neglected during small nonvolant mammal inventories: the wet grasslands, a groundwater-susceptible flooded habitat. These findings provide evidence that including these environments is mandatory for adequately sampling the small nonvolant mammal assemblage in the Cerrado domain, as well as using integrative methods for species identification.