Massive kangaroos survived till 6,500 years in the past at the New Guinea coast

More or less 50,000 years in the past, a kangaroo in contrast to any alive lately lived within the mountain rainforests of New Guinea.

First found out through Western science in 1983, Protemnodon tumbuna was once kind of the dimensions of a contemporary purple kangaroo however a lot more stocky and muscular. Maximum peculiarly, it hopped little, if in any respect. It moved most commonly on all fours, with lengthy, robust forelimbs offering beef up for agile bounding via advanced and steep terrain.

This ordinary animal was once one of the megafauna that when roamed Australia and New Guinea. It’s concept to have long gone extinct some 20,000 to 50,000 years in the past.

Then again, our new learn about, revealed within the magazine npj Biodiversity, suggests Protemnodon tumbuna survived till as overdue as 6,000 years in the past in northern New Guinea.

This constitutes forged proof the Australian and New Guinean megafauna didn’t all cross extinct on the identical time, however that some held on for for much longer than others. It additionally contributes to a extra advanced symbol than standard arguments about what drove the extinction of megafauna.

Clues from Papua New Guinea

All seven Protemnodon species had long gone extinct in Australia through 41,000 years in the past, together with just about all different megafauna species. Whether or not the general extinctions on this procedure have been pushed basically through local weather exchange or human overhunting stays closely debated.

However in New Guinea, the proof is mounting against a quite other tale.

On the Nombe rockshelter, within the highlands of japanese Papua New Guinea, fossils of Protemnodon tumbuna display it lived in the neighborhood till 22,000 to 27,000 years in the past, throughout the ultimate ice age.

Extra proof of late-surviving Protemnodon tumbuna in New Guinea got here in 2024 with the invention of a unmarried teeth from Lachitu cave, positioned within the foothills of the Oenake Vary, at the northwest coast of Papua New Guinea.

The teeth had come from a limestone deposit dated 18,000 years outdated or more youthful, even though it’s unclear whether or not the teeth itself was once additionally that contemporary.

In 2004, archaeological excavations at Taora – a rockshelter simply west of Lachitu – produced a big choice of well-preserved animal stays.

After most sea ranges receded 6,800 years in the past, Taora was once used intensely through other folks exploiting within sight marine and rainforest sources. Over the following 1,500 years, they all of a sudden constructed up a dense deposit of discarded bones and shells, and masses of small bone issues that most likely tipped fishing spears or arrows.

Archaeological excavation at Taora rockshelter in 2004 which discovered the megafauna fossil.
Anthony Barham

Our discovery

Whilst analyzing this wealthy assortment to know how historic other folks had lived within the dense coastal rainforest, one bone stood out to us.

It was once from the finger of a macropodid – a member of the kangaroo circle of relatives – however one a lot greater than any species of marsupial present in New Guinea lately.

Suspecting it represented an unrecorded species, we when put next the specimen’s form and measurement to as many extant and extinct macropodids as conceivable to decide which one it most likely belonged to.

The Taora fossil is obviously other to all lately residing macropodids. It’s maximum very similar to individuals of Protemnodon – particularly, the New Guinean species Protemnondon otibandus.

This species is considered the traditional ancestor of Protemnodon tumbuna, for which no fossils of the finger bones are recognized.

The fossil has some distinctive characteristics that distinguish it from different Protemnodon species, together with very outstanding projections above the realm the place this center finger bone joins to the claw.

However at the complete, it intently resembles many species within the genus. And because we all know Protemnodon tumbuna was once provide within the native space (a couple of kilometres away), possibly as not too long ago as 18,000 years in the past, the fossil from Taora in all probability belongs to it.

A collection of close-up images of small bones.

The large kangaroo fossil from Taora, a finger bone which most likely belongs to Protemnodon tumbuna.
Loukas Koungoulos

A tale of prolonged survival

Learn along side the present proof from Nombe and Lachitu, the Taora fossil presentations other folks will have to have co-existed with some species of megafauna for tens of hundreds of years. They’d have performed so whilst additionally growing agriculture and village-dwelling societies in New Guinea.

That’s a some distance cry from the “overkill” style, which implies the earliest First Countries other folks of Australia and New Guinea all of a sudden hunted all last megafauna to extinction.

This doesn’t imply other folks couldn’t have contributed by hook or by crook to the extinctions. However it does level to a fancy state of affairs and the important thing position of every species’ distinctive biology and ecology in how they fared towards human looking and finer-scale habitat exchange.

At the north coast of New Guinea, each elements have been most likely at play.

Research of Protemnodon enamel from Mount Etna in central japanese Queensland have discovered those kangaroos had small house levels. They didn’t transfer some distance with the intention to forage or migrate, an inclination that would go away them extraordinarily susceptible to habitat loss.

Drying climates during the last few hundred thousand years ceaselessly shrank their highland rainforest habitat in New Guinea – and stimulated the fast expansion of within sight human populations. Sooner or later, the habitat turned into so small it couldn’t beef up a viable inhabitants of those historic kangaroos.

Trapped and not able to achieve their more and more far-off house, the ultimate massive kangaroos of New Guinea’s north coast would have temporarily succumbed to even gentle looking force, becoming a member of different uncommon marsupials that disappeared from this area on the identical time within the face of post-glacial environmental adjustments.

As we proceed to discover the fossil secrets and techniques of this far flung segment of New Guinea, there might but be extra twists within the tale of Australia and New Guinea’s shared palaeohistory.