A 10-year study of museum specimens has identified two previously unknown bandicoot species and revealed that the quenda once lived much farther east than scientists believed.
Researchers examined hundreds of historical and modern specimens from museums worldwide. Using DNA analysis and skull measurements, they reassessed how different bandicoot populations related to each other. The findings appear in the Australian Journal of Taxonomy.
The team identified the little brown bandicoot (Isoodon microtis) from South Australia as a distinct species that became extinct around a century ago. They also determined that the New Guinea brown bandicoot (Isoodon moresbyensis), previously classified as a subspecies of the northern brown bandicoot, qualifies as its own species.
The research showed South Australia once hosted three bandicoot species, not one as previously thought. The quenda (Isoodon fusciventer), long regarded as exclusively Western Australian, once lived around Adelaide, Kangaroo Island and the Nuyts Archipelago. This represents a major eastward extension of the species' known range.
Researchers also described several new subspecies: two of the golden bandicoot, four of the quenda, and one of the northern brown bandicoot from Cape York in Queensland.
The findings carry conservation implications. The quenda's broader range suggests it may face lower extinction risk than previously believed, though South Australian populations remain small. The southern brown bandicoot, already listed as endangered, now appears to have a more restricted range than once thought, potentially facing greater conservation risk under the new classification.