Answer:
There used to be two species of bilby, the Greater Bilby and the Lesser Bilby. The Lesser Bilby, Macrotis luecura is believed to have become extinct some time between the 1930s and 1950s. Now, there is just the Greater Bilby, Macrotis lagotis, which is listed as "vulnerable", federally, with a population trend status "decreasing". It is listed as "endangered" in Queensland.
For more details, please see sites listed below.