"In Australia, there are several Old Endemic native rodent species, whose ancestors arrived there several million years ago, that are under serious threat of extinction including two rock rat species—the Central Rock rat (Zyzomys pedunculatus) and the Carpentarian Rock rat (Z. palatalis)," says Professor Bill Breed from the University of Adelaide, South Australia. To read more about Australian native mice and rats, see Native mice and rats: Australian natural history series.