title: Oldest fossil remains of the enigmatic pig-footed bandicoot show rapid herbivorous evolution.
abstract: The pig-footed bandicoot,Chaeropus ecaudatus,is one of the most enigmatic Australian marsupials, which went extinct in the late 1950s probably as a result of European colonization. It is unusual in being the only marsupial to have evolved reduction of digits on both fore and hind feet, with the forefeet being pig-like (two toes) and the hind feet being horse-like (one toe). According to molecular phylogenetic analyses,Chaeropusdiverged from other bandicoots (Peramelidae), and the bilbies (Thylacomyidae) by the mid-Late Oligocene. This is considerably earlier than suggested by the fossil record, with the current oldest specimens being Late Pleistocene in age. Here, I report the oldest fossils ofChaeropus,representing a new species,Chaeropus baynesifrom the Late Pliocene to Early Pleistocene (2.47-2.92 Ma) Fisherman's Cliff Local Fauna, Moorna Formation, New South Wales, Australia, and extending the fossil record of the genus and family by at least 2 million years.Chaeropus baynesiis less high crowned thanC. ecaudatusand lacks lateral blade development on lower molars, suggesting that it was unlikely to be grazing. This suggests thatChaeropusmust have adapted rapidly to the drying conditions and changes in environments, and would have become a grazer in a very short period of time.
authors.affiliation: Western Australian Museum , Welshpool, Western Australia 6106 , Australia.
authors.forename: Kenny J
authors.identifier: 0000-0003-1734-4742
authors.initials: KJ
authors.lastname: Travouillon
keywords: Chaeropus; Fisherman's cliff; Peramelemorphia; Pliocene; arid adaptation; new species