A decade-long study of museum specimens from around the world has identified two previously unrecognised bandicoot species and several new subspecies, while revealing that researchers believe one of the newfound species became extinct around a century ago.
The research, published in the Australian Journal of Taxonomy, examined hundreds of historical and modern specimens of short-nosed or brown bandicoots (genus Isoodon). The team, including researchers from the Western Australian Museum, the South Australian Museum and Queensland University of Technology, used DNA analysis and detailed skull measurements to reassess relationships between populations.
Among the most significant findings was the recognition of the little brown bandicoot (Isoodon microtis), a newly described species from South Australia that the researchers believe became extinct around a century ago. Specimens had sat unnoticed in museum collections for generations, and were found to be distinct enough from other bandicoots to warrant species status.
The study also elevated the New Guinea brown bandicoot (Isoodon moresbyensis), previously regarded as a subspecies of the northern brown bandicoot, to species level.
The research dramatically altered understanding of bandicoot diversity in South Australia. Previous classifications suggested only one species, the southern brown bandicoot, occurred in the state. The revision found that South Australia was once home to three species: the southern brown bandicoot, the newly recognised little brown bandicoot, and the quenda (Isoodon fusciventer), which had long been regarded as a Western Australian species. The team found it once lived around Adelaide, Kangaroo Island and the Nuyts Archipelago, representing a major eastward extension of the species' known historical range.
The study also identified 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 discoveries have implications for conservation. For the quenda, the newly recognised broader range suggests the species may be less threatened overall than previously believed, though the researchers caution that South Australian populations remain small and require ongoing protection. Conversely, the revised distribution of the southern brown bandicoot suggests its range is more restricted than once thought; already listed as endangered, the species may face an even greater conservation risk under the new classification.
The team now plans to extend their work to long-nosed bandicoots (genus Perameles), a group from which five species have already disappeared since European settlement.
Analysis
Why This Matters
- The discovery of a previously unrecognised extinct species highlights gaps in scientific knowledge about Australia's biodiversity loss since European colonisation.
- The revised species boundaries change conservation priorities: the southern brown bandicoot may be more endangered than previously assessed, while the quenda's broader historical range may reduce its overall threat status.
- The findings demonstrate the value of museum collections as sources of new scientific discoveries, even from specimens collected more than a century ago.
Background
Bandicoots are rabbit-sized marsupials found in Australia and New Guinea, distinguishable by their long-pointed snouts, large back legs and short tails. They are omnivores that dig for food. There are more than 20 living species of bandicoots, but several Australian species have gone extinct since European colonisation. The short-nosed or brown bandicoots in the genus Isoodon previously comprised five living species known in Australia and New Guinea. While some species remain widespread, others have suffered severe decline due to habitat loss, changing fire patterns and introduced predators.
Key Perspectives
Study authors: The recognition of the little brown bandicoot as a species that became extinct around a century ago carries mixed emotions: it is sobering that a unique Australian mammal disappeared before science even recognised it.
Study authors: For the quenda, the newly recognised broader range suggests the species may be less threatened overall, but South Australian populations remain small and require ongoing protection.
Study authors: The revised distribution of the southern brown bandicoot suggests its range is more restricted than once thought; already listed as endangered, the species may face an even greater conservation risk under the new classification.
What to Watch
- Whether the revised species boundaries lead to changes in conservation listings, particularly for the southern brown bandicoot and quenda.
- The team's next phase of research on long-nosed bandicoots, from which five species have already disappeared since European settlement.
- Whether the methods used in this study, combining museum specimen analysis with DNA, are applied to other Australian mammal groups and yield further undiscovered diversity.
Checked
12 claims in this story checked against 1 source: 10 supported.
Show each claim
- SupportedTwo previously unrecognised bandicoot species were identified, and researchers believe one became extinct around a century ago.The Conversation – Articles (AU): “A ten-year scientific investigation of museum specimens has uncovered two previously unrecognised bandicoot species”
- SupportedThe study used DNA analysis and detailed skull measurements.The Conversation – Articles (AU): “Using DNA analysis and detailed skull measurements, we reassessed how different bandicoot populations were related.”
- SupportedThe quenda once ranged into South Australia.The Conversation – Articles (AU): “However, we found it once lived around Adelaide, Kangaroo Island and the Nuyts Archipelago.”
- Not in the sourcesThe research was published in the Australian Journal of Taxonomy.The Conversation – Articles (AU): “New species distribution for the seven species of the brown bandicoots. Travouillon et al. / Australian Journal of Taxonomy”
- Partly supportedThe research team included researchers from the Western Australian Museum, the South Australian Museum and Queensland University of Technology.The Conversation – Articles (AU): “Kenny Travouillon works for the Western Australian Museum. ... Steve Cooper works for the South Australian Museum and Adelaide University”
- SupportedThe study examined hundreds of historical and modern museum specimens from around the world.The Conversation – Articles (AU): “Our new study examined hundreds of historical and modern specimens from museum collections around the world.”
- SupportedThe little brown bandicoot was recognised as a newly described species from South Australia, and the researchers believe it became extinct around a century ago.The Conversation – Articles (AU): “Among the most significant findings was the recognition of the little brown bandicoot (Isoodon microtis), a newly described species from South Australia. We believe it became extinct around a century ago.”
- SupportedThe New Guinea brown bandicoot was elevated from a subspecies of the northern brown bandicoot to species status.The Conversation – Articles (AU): “Our study also found that the New Guinea brown bandicoot (Isoodon moresbyensis), previously regarded as a subspecies of the northern brown bandicoot (Isoodon macrourus), was actually a species in its own right.”
- SupportedThe revision found that South Australia was once home to three bandicoot species, including the quenda.The Conversation – Articles (AU): “However, the revision found that South Australia was once home to three species: the southern brown bandicoot (Isoodon obesulus), the newly recognised little brown bandicoot, and the quenda (Isoodon fusciventer).”
- SupportedThe quenda once lived around Adelaide, Kangaroo Island and the Nuyts Archipelago.The Conversation – Articles (AU): “However, we found it once lived around Adelaide, Kangaroo Island and the Nuyts Archipelago.”
- SupportedThe study identified two new golden bandicoot subspecies, four quenda subspecies and one northern brown bandicoot subspecies from Cape York.The Conversation – Articles (AU): “We 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.”
- SupportedThe quenda’s broader recognised range may mean it is less threatened overall than previously believed, while South Australian populations remain small and need ongoing protection.The Conversation – Articles (AU): “For the quenda, the newly recognised broader range suggests the species may be less threatened overall than previously believed. However, we caution that South Australian populations remain small and require ongoing protection.”
