A strange enormous kangaroo used to wander the steep jungles of New Guinea long ago—almost all the way up to the end of the last ice age.
According to studies I and my colleagues published, this kangaroo was not closely connected to kangaroos that live in Australia today. Instead, it represents a distinct species of primitive kangaroo found only in New Guinea.
The age of megafauna
Megafauna, or enormous creatures, were formerly common in Australia before the majority of them died extinct roughly 40,000 years ago. The kangaroos, koalas, crocodiles, and other creatures that we now associate with the Australian wilderness coexisted with these megafauna, although many of them were bigger species of these.
There were three-ton Diprotodon optatums, 2.5-meter-tall short-faced kangaroos, and huge Phascolonus wombats (the largest marsupial ever). In reality, certain Australian megafaunal species still exist today, including the red kangaroo, emu, and cassowary.
In comparison to Australia, New Guinea's fossil megafauna has received far less research. In comparison to Australia, New Guinea's fossil megafauna has received far less research. Though mysterious, the fossil record from New Guinea has revealed signs of interesting and strange species whose evolutionary histories are intertwined with those of Australia.
A few trips and fossil digs by American and Australian researchers in the 1960s, 1970s, and 1980s were conducted in New Guinea by paleontologists.
Two jaws of an extinct gigantic kangaroo were discovered in the early 1970s during an archaeological dig directed by Mary-Jane Mountain. Tim Flannery, a teenage scientist who is now a professor, gave the species the name Protemnodon nombe.
The fossils Flannery spoke about date back between 20,000 and 50,000 years. They originate from the Nombe Rockshelter, a palaeontological and archaeological site in central Papua New Guinea's highlands. This location also included fossils of a different species of kangaroo and enormous four-legged marsupials known as diprotodontids.
An unexpected finding I just reexamined the fossils of Protemnodon nombe with Professor Gavin Prideaux of Flinders University, and we uncovered something. This odd kangaroo was not a member of the Protemnodon genus, which was formerly found throughout Australia, from Tasmania to the Kimberley. It was something far stranger and more archaic.
It stands apart from other known kangaroos in particular because of its distinctive molars, which include curving enamel crests. We called the species Nombe nombe after moving it into a brand-new genus that is exclusive to New Guinea.
Our research suggests that Nombe may have descended from an ancient kangaroo that crossed the Pacific from Australia into New Guinea in the late Miocene era, about 5-8 million years ago.
Due to lower sea levels during the time, the islands of New Guinea and Australia were united by a land bridge; now, the Torres Strait separates them.
Early Australian animals, such as the megafauna, were able to travel to the rainforests of New Guinea because to this "bridge." These animal groups split off from their Australian counterparts when the Torres Strait flooded again, and they later developed independently to fit their tropical and mountainous New Guinean habitat.
We now think of Nombe as descended from one of these long-extinct kangaroo groups. The hunchbacked, hulking animal lived in a varied, hilly jungle with dense vegetation and a closed canopy. It developed a large jawbone and powerful chewing muscles since it had to devour the rough leaves of trees and plants.
Only two fossil lower jaws of the species are presently known. There is still a lot to be learned. Do contemporary kangaroos hop like Nombe? How did it go extinct?
A single finding in paleontology typically leads to a plethora of additional inquiries.
Strange but familiar animals
Despite being extremely peculiar and fascinating, little is known about the indigenous animal life of New Guinea outside of the island. Few Australians have any real knowledge of what is just over the strait.
Early on in my PhD, I visited the Papua New Guinea Museum in Port Moresby, and I was blown away by the species I saw there. Large, long-nosed, worm-eating echidna species are still alive; one of them may weigh up to 15 kilos.
In addition, there are several species of wallaby, tree kangaroo, and possum that are extinct in Australia, as well as many more in the fossil record.
Although we sometimes assume that these animals are exclusively Australian, they also exist in New Guinea in a variety of fascinating forms.
It's strange and thrilling for an Australian biologist to observe these "Aussie" critters that have evolved into novel and bizarre forms in a different environment.
N. nombe, which is exciting for me and my coworkers, may give Fresh Guinean paleontology a new lease of life. We are a part of a small team of researchers that just received funding to conduct three excavations at two various locations in eastern and central Papua New Guinea over the course of the following three years.
