**NOT SUBBED **species may be inhabiting a sacred limestone cave network on the south-west coast near what will become known as Margaret River. Mammoth Cave is or at some point has been home to Zygomaturus trilobus, a 500kg relative of wombats and one of the largest marsupials to have ever existed, the Simosthenurus or ‘short-faced’ kangaroo, Zaglossus hacketti, the giant echidna with a half a metre-long tongue and the flesh-eating Thylacoleo or marsupial lion.