A new “type” of Pig-footed Bandicoot

The original description of the now extinct Australian Pig-footed Bandicoot was based on one specimen, since lost, from which the tail was missing. New research, from the Australian Museum and Western Australian Museum, has nominated a replacement…

The scientific value of a rare specimen in the Australian Museum recently increased following collaborative work between bandicoot guru Dr Kenny Travouillon (Western Australian Museum) and staff at the AMRI Mammalogy Collection.

There are only two specimens of the extinct Southern Pig-footed bandicoot in the Australian Museum’s mammal collection, both collected in the mid-1800s. One of these has just been designated the “neotype”, or the new name-bearing specimen of the species; therefore making this rare specimen even greater in scientific importance.

Pig-footed Bandicoots are among Australia’s least known and most unusual marsupials. These small bandicoots have long slender limbs and large ears, and as the common name suggests, their feet are quite remarkable. The number of functional toes is greatly reduced, with only one hoof-like toe on each hind foot and two on the front. An early casualty of European settlement, Pig-footed Bandicoots are thought to have died out around the 1950s. Only 32 specimens exist in world collections; some are only a broken skull or just a jaw bone, and there are only two preserved in alcohol. These few tragic remains have been sitting in world museums for 150 years or more. You might expect them to have been “studied to death”… this is not the case.

In 2019, a team led by Dr Kenny Travouillon discovered that the 32 specimens included a distinct new species for which they used an Aboriginal name, Yirratji, and the scientific name Chaeropus yirratji. A species once widely distributed across half the Australian continent was revised to three distinct forms, each with a much smaller distribution than previously thought at the time European settlers arrived. Further, they discovered that the original species Chaeropus ecaudatus comprised of two distinct subspecies (races) but most of the 32 specimens were of the new northern species, Yirratji. This radically changed the situation with regard to museum specimens. The original “Pig-foot” was reduced to an unlucky 13, nearly all being of the eastern race with a restricted distribution, and only one specimen in existence of the western race (other than subfossils).

The original specimen or type specimen of, Chaeropus ecaudatus , was part of the Australian Museum collection in 1860 but disappeared soon after, and is presumed to have been lost. A type specimen is the specimen upon which the name is based, and is the reference specimen for the species, should there be any doubts about what the species actually is. The naming of a second species of Pig-footed Bandicoot and recognition of two new subspecies in 2019 meant that a different specimen, the “neotype” or new type specimen, must be selected to represent Chaeropus ecaudatus. Species are named by publishing the new name, in addition to a description of the unique features of the new species and how it differs from closely related species. Accordingly, type specimens have great scientific value and once a specimen is designated as a type it remains one despite future changes in taxonomy. Sometimes scientists need additional information, not included in the species description, to resolve an issue with classification. For this they can inspect the type specimen.

One of the many treasures in the Australian Museum Mammal collection is a skull and skeleton of the Pig-footed Bandicoot, collected in 1857 near Mildura, by renowned scientist and museum Curator, Gerard Krefft. Only 12 specimens exist in world collections of this eastern race of the extinct Pig Footed Bandicoot (Chaeropus ecaudatus ecaudatus). Of these, a specimen in the Mammal collection is one of only two in existence that also has a skeleton; the rest were prepared as skins and the skeleton discarded. The AM specimen was an obvious choice as a neotype. It is unique because it consists of both a skull with unworn teeth and a skeleton, that displays key dental features diagnostic of the subspecies - essential prerequisites for a neotype. The only other specimen in the world with a skeleton has worn teeth.

Research into the Pig-footed Bandicoot demonstrates that profound changes in our knowledge of Australian mammals continue to emerge, even when the specimens have been scrutinised by scientists for over 200 years. It has also led to another species being added to the list of Australian mammals to go extinct since European settlement.

Dr Harry Parnaby, Research Associate, Mammalogy Collection, Australian Museum Research Institute

Dr Sandy Ingleby, Collection Manager, Mammalogy Collection, Australian Museum Research Institute

More information:

• Travouillon, Kenny J., H. Parnaby and S. Ingleby. 2020. Neotype designation for the Australian Pig-footed Bandicoot Chaeropus ecaudatus Ogilby, 1838. Records of the Australian Museum 72(3): 77–80. https://doi.org/10.3853/j.2201-4349.72.2020.1761
• Travouillon, K. J., B. F. Simoes, R. Portela Miguez, S. Brace, P. Brewer, D. Stemmer, G. J. Price, J. Cramb, and J. Louys. 2019. Hidden in plain sight: reassessment of the pig-footed bandicoot, Chaeropus ecaudatus (Peramelemorphia, Chaeropodidae), with a description of a new species from central Australia, and use of the fossil record to trace its past distribution. Zootaxa 4566(1): 1–69. https://doi.org/10.11646/zootaxa.4566.1.1, and Research Gate.