A ten-year scientific investigation of museum specimens has uncovered two previously unrecognized bandicoot species and several new subspecies within the genus *Isoodon*, the short-nosed or brown bandicoots of Australia and New Guinea.

Writing in the Australian Journal of Taxonomy, researchers including Kenny Travouillon, Matthew Phillips, Steve Cooper and Terry Bertozzi examined hundreds of historical and modern specimens from museum collections around the world.

One newly described species, the little brown bandicoot (*Isoodon microtis*) from South Australia, is believed to have gone extinct around a century ago, its specimens sitting unnoticed in collections for generations.

The other, the New Guinea brown bandicoot (*Isoodon moresbyensis*), was previously regarded as merely a subspecies of the northern brown bandicoot.

The little brown bandicoot's recognition carries mixed emotions: it is a remarkable taxonomic find, but it means a unique Australian mammal disappeared before science ever recognized it existed.

That is the kind of reversal a nature reader rarely hears about — a species described a hundred years after it was lost. The broader revision also reshaped South Australian biogeography.

Previous classifications suggested only one bandicoot species, the southern brown bandicoot, occurred in the state, but the study found the region was once home to three species, including the newly recognized little brown bandicoot and the quenda (*Isoodon fusciventer*), long regarded as a Western Australian species that once lived around Adelaide, Kangaroo Island and the Nuyts Archipelago.

The project began in 2016 when Travouillon traveled through Europe and the United States studying bandicoot specimens collected more than a century ago, and found existing classifications might not be right.

The team then collected measurements and genetic samples from museums across Australia and New Guinea, bringing in collaborators through the OZ Mammals Genomics initiative.

Using DNA analysis and detailed skull measurements, the researchers reassessed how bandicoot populations were related and identified overlooked species and subspecies.

The study, published in the Australian Journal of Taxonomy, described two new subspecies of golden bandicoot, four of the quenda, and a new subspecies of the northern brown bandicoot from Cape York in Queensland.

Taxonomy underpins conservation planning, and the reclassification shifts how extinction risk is understood and how resources are allocated.

The quenda's newly recognized broader historical range suggests it may be less threatened overall than previously believed, though the researchers caution that its South Australian populations remain small and need ongoing protection.

The opposite applies to the southern brown bandicoot: its revised range is more restricted than once thought, and a species already listed as endangered may face even greater risk under the new classification.

Next, the team turns to long-nosed bandicoots of the genus *Perameles*, five species of which have disappeared since European settlement.