Middle Holocene survival of marsupial megafauna on the north coast of New Guinea.

The timing and causes of the extinction of Pleistocene megafauna are unresolved issues in the natural history of Australia and New Guinea (Sahul). In Australia, megafauna are believed to have become extinct by c. 41ka, but in the Highlands of New Guinea some species persisted until the Last Glacial Maximum (LGM), as late as c. 22ka. Here, we present the first evidence that one of these taxa survived beyond even this timeframe. We describe a manual phalanx from a megafaunal macropodid, probably referable to a quadrupedal, forest-dwelling member of the genus Protemnodon recovered from the Middle Holocene (6.8 - 5.3ka) archaeological deposit of Taora, a coastal rockshelter located west of Vanimo, Papua New Guinea. This late local persistence is likely a consequence of low human populations and a relatively small body size. Its disappearance from the region is coincident with broader decline in local mammalian diversity following post-glacial environmental change. Taora provides the first indication that any of Sahul's megafauna survived beyond the end of the LGM and highlights geographic and chronological variability in this diverse group's extinction history.