The Pig-Footed Bandicoot or Chaeropus ecaudatus, is supposed to have gone extinct with the last sighting in 1921. They differed from other bandicoots in that they had a caecum ( a little organ before the large intestine designed to digest cellulose, mainly found in low-nutrient vegetation like grasses). They also ran unlike other marsupials; using primarily their forelegs while dragging their hind legs along.
This little animal had a huge range spanning all of West and South Australia. They were small in size, about 25 cm in length, with the tail another 15 cm long. We know that they made shallow nest in scrubby woodlands and grassy plains. They carried two babies in the pouch and had a mostly vegetarian diet interspersed with insects.
The last body sample was collected in 1907 ( the header image of this article) and the last sightings were said to have been made as late as the 1950’s. The main cause of their extinction is said to the introduction of cattle that destroyed the habitat and hiding places. Other invasive species like rabbits did the same and out-populated them. Yet other invasive species like foxes( yes, some Australians were rather keen on fox-hunting) preyed on them.
In Cryptid literature there have been continued sightings of them up to the present day. Their territory was rather huge so there is a tiny smidgen of possibility that they might still be around. Stranger things have happened after all.