The genus was present until at least about 45,000 years ago before going extinct, although some evidence indicates it may have survived to as recently as 18,000 years ago. Its extinction may have been due to climate shifts during the Pleistocene, or to human hunting. Those who support the hypothesis of a human-mediated extinction process cite that the arrival of humans to continental Australia occurred around the same time as the disappearance of this species. More evidence that this extinction was facilitated by human interaction is that the time period in which the extinction occurred was characterised by a relatively stable climate. However, no evidence of predation on or consumption of "P. goliah" by humans has been found in the fossil record.