Leichhardt, Ludwig "Beiträge zur Geologie von Australien," Abhandlungen Naturforschende Gesellschaft zu Halle, Vol. 3 (1855)

It is possible that it [Diprotodon] is at the present time still living in the tropics of this country, which are rich in water. This I was told by Mr. Dennis, that the blacks speak of extensive lakes and gigantic animals.