Chaeropus, known as the pig-footed bandicoots, is a genus of small marsupials that became extinct during the 20th century. They were the only members of the family Chaeropodidae in order Peramelemorphia (bandicoots and bilbies), with unusually thin legs, yet were able to move rapidly. Two recognised species inhabited dense vegetation on the arid and semiarid plains of Australia. The genus' distribution range was later reduced to an inland desert region, where it was last recorded in the 1950s; it is now presumed extinct.
Taxonomy
The genus was proposed by William Ogilby in a presentation to the Linnean Society of London of a new species tentatively assigned to a genus of bandicoots, the long-nosed Perameles, and was forwarded to John Gould, then at Sydney, for a more detailed examination. Ogilby submitted a drawing by collector Major Mitchell, who also supplied extensive remarks on the animal's form and habits, and identified the unusual pig-like toes of the forelimbs as the basis for a new genus. The collection of the specimen was made at the interior of New South Wales by Mitchell, on the banks of the Murray River.
The genus name Chaeropus combines terms from Ancient Greek for "pig" and "foot", a reference to the unique characteristic of the forelimbs noted by the describing author. The specific epithet ecaudatus refers to the absence of a tail, which the single specimen happened to be missing, leading to the unfortunate suggestion by the name that the marsupial did not possess them.
The recognised synonymy of the genus was published by Theodore S. Palmer in 1904. A nomenclatural synonym, Chœropus [Choeropus] Waterhouse, G.R. 1841, was published several years after Ogilby as an unjustified emendation; Waterhouse gives the spelling proposed by Ogilby in the same work. Oldfield Thomas noted the inappropriate epithet ecaudatus in 1888, substituting the name Chœropus castanotis proposed by John Edward Gray as the type of the genus, but this was suppressed as a synonym by Palmer.
The vernacular description, pig-footed bandicoot, was given by Ogilby in his first description, a name ascribed by Mitchell's party. Europeans settlers reported the species as resembling "small antelopes", a simile that was reported by Bernard Woodward as persisting until their disappearance around 1900. The names recorded from the Noongar language are and . According to Indigenous Australian trackers, the pig-footed bandicoot was known as landwang and tubaija in their culture.
Classification
This genus was previously placed in the family Peramelidae, along with the bilbies, as the subfamily Chaeropodinae by McKenna and Bell (1997). However, its form is quite distinct, and recent molecular evidence supports this distinction. It is believed to be the sister group of the rest of the Peramelemorphia, and has been assigned to its own family, the Chaeropodidae. The divergence of Chaeropus from other members of the Peramelemorphia is estimated to be in the Mid-Late Oligocene, around 26.7 Mya (21.9–31.3 confidence interval).
Until 2019, both species were grouped under C. ecaudatus as the pig-footed bandicoot; however, a 2019 study split the genus into two species - the northern pig-footed bandicoot (C. yirratji) and the southern pig-footed bandicoot (C. ecaudatus). In 2016, a fossil species C. baynesi was described from Late Pliocene to Early Pleistocene (2.47–2.92 Mya) of south-west New South Wales.
The arrangement within the Marsupialia, with the treatment proposed in the 2019 revision, may be summarised as:
Peramelemorphia
Thylacomyidae (Macrotis, the bilbies) Chaeropodidae Chaeropus Chaeropus ecaudatus Chaeropus ecaudatus ecaudatus Chaeropus ecaudatus occidentalis Chaeropus yirratji Peramelidae (extant genera known as bandicoots)
Description
A genus of Peramelemorphia order of marsupials, allied by a monophyletic family, and regarded as exceptional in their morphology. The direct evidence of the two species is limited to 29 specimens remaining at museums in Australia and overseas. Their superficial appearance resembled the native bandicoots or rat kangaroos, although very small and dainty, and comparable to the size of a young rabbit or kitten.