According to a new study, a big kangaroo that previously wandered on four legs through inaccessible forests in the Papua New Guinea Highlands may have lived as recently as 20,000 years ago, long after large-bodied megafauna on mainland Australia became extinct.

Reign of Papua New Guinea Highland's megafauna lasted long after humans arrived
(Photo : ROSLAN RAHMAN/AFP via Getty Images)

To better comprehend PNG's fascinating natural past, paleontologists, archaeologists, and geoscientists employed modern tools to re-examine megafauna bones from the famous Nombe Rock Shelter fossil site in Chimbu Province, as per ScienceDaily.

According to a new study, a big kangaroo that previously wandered on four legs through inaccessible forests in the Papua New Guinea Highlands may have lived as recently as 20,000 years ago, long after large-bodied megafauna on mainland Australia became extinct.

To better comprehend PNG's fascinating natural past, paleontologists, archaeologists, and geoscientists employed modern tools to re-examine megafauna bones from the famous Nombe Rock Shelter fossil site in Chimbu Province.

The revised dates of the bones indicate that numerous big animal species, including the extinct thylacine and a panda-like marsupial (named Hulitherium Tomasetti), were still present in the PNG Highlands when people first arrived, potentially about 60,000 years ago.

Surprisingly, two gigantic extinct kangaroo species, one of which bounded on four legs rather than two, may have survived in the region for another 40,000 years.

If these megafaunal species did persist in the PNG Highlands for considerably longer than their Australian counterparts, it might be because people only visited the Nombe region infrequently and in small numbers until after 20,000 years ago.

According to ANU Professor of Archaeological Science Tim Denham, co-lead author of the new study published in the journal Archaeology in Oceania, Nombe rock shelter is the only site in New Guinea known to have been occupied by people for tens of thousands of years and preserves remain of extinct megafaunal species, the majority of which are unique to New Guinea.

New Guinea is a forested, mountainous northern part of the formerly larger Australian continent known as 'Sahul,' but our knowledge of its fauna and human history is limited compared to that of mainland Australia, according to Professor Denham, who first conducted fieldwork in the PNG Highlands in 1990.

According to Flinders University Palaeontology Laboratory co-author Professor Gavin Prideaux, the latest Nombe study is consistent with similar evidence from Kangaroo Island previously produced by Flinders paleontologists, which also suggests megafaunal kangaroos may have persisted to around 20,000 years ago in some of the continent's less accessible areas.

Many broad assumptions regarding megafaunal extinction timescales, he claims, have been "more destructive than beneficial."

Archaeologists originally explored the underground rock shelter in the 1960s, but the most extensive period of fieldwork was done between 1971 and 1980 by ANU archaeologist Dr. Mary-Jane Mountain, who is also the author of the newest publication. Her original study produced the first complete description and interpretation of the Nombe site, and she was essential in changing our knowledge of the PNG Highlands' human history.

"Mary-Jane (Mountain) originally hypothesized that megafauna at the location may have persisted for tens of millennia after human settlement," Professor Denham explains.

Read more: Marine Megafauna Extinction: Huge Loss in Functional Diversity

Megafauna

Megafauna in Australia includes the enormous wombat-shaped Diprotodon and the massive goanna Megalania, as per Australian Museum.

Woolly Rhinoceroses, Mammoths, Cave Lions, and Cave Bears were among the European Megafauna.

Megafauna in North America featured Giant Ground Sloths and Sabre-toothed Tigers, while elephants, giraffes, rhinoceroses, and hippopotamuses were found in Africa. Africa's Megafauna is all that is left today.

The global extinction of megafauna was most likely caused by environmental and ecological reasons. It was nearly finished at the end of the previous ice age.

It is thought that megafauna evolved in reaction to glacial circumstances and became extinct with the emergence of warmer temperatures.

Megafauna extinction in temperate Eurasia and North America occurred along with the replacement of huge periglacial tundra by enormous areas of woodland.

 Glacial species such as mammoths and woolly rhinoceros were displaced by forest-adapted mammals such as elk, deer, and pigs.

Reindeer (caribou) went north, while horses went south to the Central Asian steppe.

Even though humans colonized North America less than 15 000 years ago and non-tropical Eurasia approximately 1 million years ago, this all happened around 10 000 years ago.

Climate change has been less severe in tropical and subtropical locations. The transformation of a broad section of north Africa into the world's biggest desert was the most spectacular of these shifts.

Africa, as well as tropical and subtropical Asia, averted catastrophic faunal extinction.

The Asian elephant has survived to the current day, whereas the Asian rhinoceros has survived even on the comparatively small Indonesian island of Java.

Related article: North America's Megafauna Likely Went Extinct Because of Climate Change