Overview
Research indicates that a species of ancient giant kangaroo, *Protemnodon anak*, survived on the coastal lowlands of New Guinea until approximately 6,500 years ago. This date post-dates evidence of its disappearance from mainland Australia by tens of thousands of years. The survival of this megafauna in New Guinea until a comparatively recent period suggests a more nuanced timeline for the extinction of large marsupials in the region than previously understood.
Research Context
Roughly 50,000 years ago, a kangaroo species, *Protemnodon anak*, inhabited the mountain rainforests of New Guinea. This species was distinct from kangaroos known today. The general understanding of megafauna extinction events across Sahul (the continental landmass comprising Australia, New Guinea, and Tasmania during periods of lower sea levels) has primarily centered on mainland Australia. The accepted extinction timeframe for most Australian megafauna is around 40,000 to 50,000 years ago. This current investigation focused on examining the historical presence and survival duration of *Protemnodon anak* in the New Guinea context, specifically its coastal lowlands.
Approach
The study involved the re-examination and dating of fossil material from the Nombe Rockshelter in the Chimbu Province of Papua New Guinea. The rockshelter, located in the New Guinea Highlands, is an archaeological and paleontological site. Researchers previously proposed that Protemnodon anak was extinct in the New Guinea Highlands by approximately 18,000 years ago. However, the current research focused on whether there was evidence of its presence at more recent dates in different ecological zones of New Guinea, specifically the coastal regions.
Findings
- Fossil evidence indicates the presence of *Protemnodon anak*, a large, ancient kangaroo species, in New Guinea.
- This species persisted on the coastal lowlands of New Guinea until approximately 6,500 years ago.
- This survival date follows the generally accepted extinction date for most Australian megafauna, including *Protemnodon anak* on mainland Australia, by tens of thousands of years.
- Previously, it had been thought that *Protemnodon anak* became extinct in the New Guinea Highlands around 18,000 years ago.
Why This Matters
The observed late survival of *Protemnodon anak* in New Guinea's coastal lowlands challenges the established understanding of megafauna extinction timelines across Sahul. It indicates that the processes and timing of these extinctions may have varied geographically within the larger continental mass, with specific environments potentially acting as refugia for some species for extended periods. This finding suggests that human impact or paleoenvironmental changes did not lead to a uniform or simultaneous extinction event across all parts of Sahul for certain megafaunal species.