The dominance of Papua New Guinea’s megafauna lasted long after the arrival of humans

A giant kangaroo that once roamed the remote forests of Papua New Guinea’s highlands on all fours may not have survived until 20,000 years ago – long after the large-scale megafauna became extinct on mainland Australia, new research shows.

Flinders University paleontologists, in collaboration with Australian National University archaeologists and geoscientists, have used new techniques to re-examine megafauna bones from the rich Nombe Rock Shelter fossil site in Chimbu province, to better understand PNG’s fascinating natural history.

The new analysis revealed a revised age of the bones and suggests that several large mammal species, including the extinct thylacine and a panda-like marsupial (dubbed Hulitherium tomasettii), were still living in the PNG Highlands when humans first arrived around 60,000 years ago.

Notably, two large extinct kangaroo species, including one that jumped on four legs instead of hopping on two legs, may have persisted in the region for another 40,000 years.

“If these megafauna species actually survived much longer in the PNG Highlands than their Australian counterparts, it could be because people visited the Nombe area infrequently and in small numbers until 20,000 years ago,” says ANU professor Archaeological Sciences Tim Denham, co-lead author of the new study published in the journal Archeology in Oceania.

“Nombe Rock Shelter is the only site in New Guinea known to have been inhabited by humans for tens of thousands of years and preserves remains of extinct megafauna species, most of which are unique to New Guinea.

“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 to that of mainland Australia,” says Professor Denham, who initially did fieldwork in the US performed PNG Highlands in 1990.

Research co-author Professor Gavin Prideaux of the Flinders University Paleontology Laboratory says the latest Nombe study is consistent with similar evidence from Kangaroo Island previously prepared by Flinders paleontologists and published in Journal of Quaternary Science in 2015, also suggesting that megafaunal kangaroos may have persisted in some of the continent’s less accessible areas until around 20,000 years ago.

He says that many common assumptions about the timelines of megafaunal extinctions have been “more damaging than helpful.”

“Although it is often assumed that all megafaunal species in Australia and New Guinea became extinct from coast to coast by 40,000 years ago, this generalization is not based on very much actual evidence,” says Professor Prideaux. “It’s probably more damaging than helpful in clarifying exactly what happened to the dozens of large mammals, birds, and reptiles that inhabited the continent when humans first arrived.”

The Nombe rock shelter near the communities of Nongefaro, Pila and Nola in Papua New Guinea was rarely visited by nomadic groups of highland peoples in prehistoric times.

The hidden rock shelter was first excavated by archaeologists in the 1960s, but the most intense phase of fieldwork was carried out in 1971 and 1980 by ANU archaeologist Dr. Mary-Jane Mountain, who is also the author of the latest publication. Their initial research provided the first detailed description and interpretation of the Nombe site and played a crucial role in shaping our understanding of the human history of the PNG Highlands.

“Mary-Jane (Mountain) initially hypothesized that the megafauna at the site might have survived tens of millennia after human settlement, but this has only been confirmed by the advent of new techniques in archaeology, dating, and paleontological science,” says Professor Denham.

Professor Prideaux says these new applications of modern analytical techniques or new excavations at the Nombe site would further confirm the schedules of late surviving megafauna and the duration of human occupation in Papua New Guinea.

The latest research results were published in Archeology in Oceania.