The Carpentarian pseudantechinus (Pseudantechinus mimulus) is a small, saxicoline marsupial found in the Northwest Highlands (NWH) bioregion of Queensland, and the adjacent Northern Territory (NT) and offshore islands. For a long period, it was only known from the type specimen collected in 1905 at an imprecise location on ‘Alexandria’ station in the north-east area of NT, and from the Pellew Islands in the Gulf of Carpentaria region of NT in rocky habitats dominated by a sandstone geology. Over the last 20 years, there has been a sporadic increase in records of this nationally threatened species and it is now known from at least 92 locations in the NWH, and in the north-east NT both on the mainland and offshore islands. These new records increase the known extent of occurrence of P. mimulus to approximately 57,000 km² and reveal that the species occurs on a diverse range of rock types and vegetation communities within its range. Extrapolation by Queensland Herbarium Regional Ecosystem mapping suggests that habitat for the species occurs even more widely than currently known and will be the target for future surveys.