Papua New Guinea (PNG) and Australia were once part of a larger continent and home to an incredible diversity of now-extinct mammals. Kangaroos that hopped on four legs, the Thylacine, which went extinct in a Tasmanian zoo, and giant panda-like marsupials all inhabited this place. Australia, Tasmania, and Papua New Guinea became separate landforms before humans arrived, isolating populations of the remaining megafauna.
“New Guinea is a forested, mountainous, northern part of the formerly more extensive Australian continent called ‘Sahul’ but our knowledge of its faunal and human history is poor compared with that of mainland Australia,” said Professor Denham, who initially undertook fieldwork in the PNG Highlands in 1990.
Now, researchers from Flinders University and Australian National University have re-analyzed bones from Nombe Rock Shelter to elucidate the history of PNG’s megafauna. The shelter was long occupied by humans and contains remains of many large and now extinct mammal species, many unique to PNG. It appears that many of these large mammals survived much later than their counterparts in Australia.
The analysis shows that thylacines and Hulitherium tomasettii, large bear-like marsupials, were still extant when humans arrived as early as 60,000 years ago. Two extinct kangaroos were still alive 40,000 years ago as well.
“If these megafaunal species did indeed survive in the PNG Highlands for much longer than their Australian equivalents, then it may have been because people only visited the Nombe area infrequently and in low numbers until after 20,000 years ago,” said Tim Denham, ANU Professor and co-lead author of the research published in the journal Archaeology in Oceania.
The researchers point out that much of the timeline for megafaunal extinctions is based on assumption, which isn’t always helpful.
“Although it is often assumed that all of the megafaunal species in Australia and New Guinea became extinct coast to coast by 40,000 years ago, this generalisation is not based on very much actual evidence,” said Professor Prideaux. “It is probably more harmful than helpful in resolving exactly what happened to the dozens of large mammals, birds and reptiles that were living on the continent when people first arrived.”
This research is one more piece of the puzzle to understanding the history of life on Earth and our place in it.
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By Zach Fitzner, Earth.com Staff Writer