Researchers in Australia have unearthed the fossil of a prehistoric giant kangaroo species known as Protemnodon Viator in Papua New Guinea, weighing up to 170 kilograms, breaking records for kangaroo size. This discovery came after a five-year study that also led to the identification of three unique new species, one of which weighs twice as much as contemporary male red kangaroos.
Flinders University in Australia released a study focusing on the extinct Protemnodon species, closely related to modern kangaroos but with distinct jumping behaviors. Protemnodon kangaroos lived during the Australian Pleistocene period (approximately 2.5 million to 11,700 years ago) and were part of the diprotodontid family, which includes famous giant kangaroos and wallabies.
The research was based on fossil findings from Lake Callabonna, a dry site in South Australia, excavated in 2013, 2018, and 2019. The fossils, mostly intact, were studied by a team led by Isaac Kerr, a paleontologist at Flinders University.
Two of the ancient species closely resembled modern gray kangaroos in appearance, weighing around 50 kilograms but with a more robust and muscular build. However, the newly discovered Protemnodon Viator from Papua New Guinea weighed a whopping 170 kilograms, making it the largest kangaroo ever found, about twice the size of contemporary kangaroos.
The researchers named the giant kangaroo “Viator,” which means “traveler” or “wanderer” in Latin, referencing its ability to jump quickly and efficiently. Protemnodon kangaroos were herbivores adaptating to various environments from forests to grasslands, with some individuals comparable in size to modern rhinoceroses.
Their sturdy skulls and strong jaws indicate a diet of tough vegetation, while their teeth structure allowed them to grind and process rough plant materials. The “long-faced long-necked kangaroo,” also known as the giant wallaby, was one of the most famous species within the Protemnodon genus, reaching an estimated weight of 130 kilograms.
The researchers suggest these kangaroos appeared on Earth as early as five million years ago, with the last known Protemnodon species going extinct around 40,000 years ago. The extinction of Protemnodon kangaroos, along with other large Australian marsupials, likely resulted from climate change and human activities such as hunting and habitat destruction.
Collating data from four national museums, Kerr shared the challenges of the research, involving photographing and 3D scanning over 800 specimens from Australia and Papua New Guinea, describing them in more than 100,000 words spread across a 261-page paper.
After years of study and extensive documentation, Kerr expressed excitement about publishing the research results, hoping to inspire further investigations into the lives of Protemnodon kangaroos. He mused on the uniqueness of existing kangaroos and the curiosity surrounding the behaviors of these incredible giant kangaroos.
In addition to Protemnodon Viator, Kerr’s team discovered two more species – Protemnodon Mamkurra and Protemnodon Dawsonae. Through in-depth studies on skeletal remains found in South Australia, researchers have challenged the notion that all Protemnodon kangaroos moved quadrupedally.
The latest findings suggest that only a few Protemnodon species, like the Mamkurra kangaroo, may have moved akin to quokkas or potoroos, switching between quadrupedal bouncing and bipedal jumping. The third new species, Protemnodon Dawsonae, likely had a moderate jumping ability resembling that of swamp wallabies.
Kerr underlined the rare adaptability of these closely related kangaroos to thrive in vastly distinct environments, with Protemnodon species known to inhabit different habitats ranging from the dry regions of central Australia to the high rainfall, forest-covered mountains of Tasmania and Papua New Guinea.