Giant kangaroos of the past didn't hop - they walked on all fours

Get ready to hop into a journey through time as we explore the fascinating world of ancient kangaroos, delving into an era when these remarkable creatures roamed the prehistoric landscapes of Australia.

Imagine a kangaroo – not the modern hopping creatures we all know and love – but a mammoth “giant wallaby” who roamed the Earth millions of years ago.

These colossal ancestors were a far cry from the agile, bounding kangaroos of today, embodying a different kind of majesty and movement.

Intriguing new research reveals that these extinct relatives of our contemporary kangaroos moved in quite a different fashion.

Unlike their modern descendants who are known for their characteristic hopping, these ancient giants, known as Protemnodon, exhibited a unique mode of locomotion that sheds new light on the diverse evolutionary history of marsupials.

Meet the giant wallaby kangaroos

Diving into the Pleistocene era, between two and a half million to ten thousand years ago, we introduce you to a particular extinct kangaroo species known as Protemnodon, endearingly referred to as the giant wallaby.

This fascinating period in Earth’s history saw the rise and fall of numerous unique and extraordinary creatures, with Protemnodon standing out among them.

Several of these predecessors to our modern kangaroos were far larger, but contrary to what you might assume, the latest findings suggest that they were not hopping around.

Walking the walk…on four legs

Previously, it was thought that despite their larger size, these ancient kangaroos hopped around much like their current-day descendants.

However, newly published findings from a team of researchers reveal that these mega-marsupials were primarily quadrupedal, displaying a preference for moving about on all four legs.

Billie Jones, a former masters student at the University of Bristol, had initially speculated that the giant wallaby was more likely to be quadrupedal.

The research team confirmed this theory by taking a quantitative look at the limb proportions of the animal.

An interesting discovery was that Protemnodon’s limb proportions were quite unlike that of any living kangaroos. In particular, its short feet support the assumption that Protemnodon was primarily a quadrupedal creature.

“There had been some speculation in a graduate thesis from the University of Uppsala that it might have been more quadrupedal in its habits compared to living kangaroos,” noted Jones, the lead author of the study.

“This new paper draws on a couple of previous quantitative studies that looked at the anatomy of the humerus (upper arm bone) in a diversity of mammals, and concluded that Protemnodon habitually put more weight on its forelimbs than kangaroos today.”

Diversity of movement among kangaroos

Interestingly, Protemnodon isn’t the first instance of non-hopping kangaroos discovered by the scientists at Bristol’s School of Earth Sciences.

In previous research, experts at Bristol had shown that another subfamily of kangaroos – the sthenurines – were bipedal striders instead of hoppers.

This diverse range of locomotion within the kangaroo family suggests a greater variety of habitats in ancient Australia.

Secrets held by ancient bones

Analysis of the extinct giant wallaby’s limb bones provide further evidence that Protemnodon was not well-equipped for hopping. The ankle bones, for instance, were unsuited to withstand the stresses of hopping.

Professor Christine Janis, the supervisor of the study, added that the extinct giant wallaby Protemnodon was likely a poor hopper at best.

The evidence suggests that Protemnodon most likely moved around quadrupedally, bounding on all fours similar to how tree-kangaroos move on the ground.

Ancient habitats and ecosystems

The locomotion style of Protemnodon suggests that these ancient kangaroos adapted to a diverse range of habitats.

Fossil evidence indicates that these quadrupedal kangaroos likely thrived in forested regions and grasslands, where dense vegetation and varied terrain made hopping less efficient.

Their movement on all fours would have enabled them to navigate through these environments more effectively, accessing food sources and avoiding predators.

Implications for modern conservation

Understanding the diverse locomotive adaptations of ancient kangaroos like Protemnodon provides valuable insights into the evolutionary history of marsupials.

These findings can inform current conservation efforts by highlighting the importance of preserving varied ecosystems that support different forms of locomotion.

Protecting diverse habitats ensures the survival of modern kangaroos and their relatives, allowing them to continue their unique evolutionary journeys.

The study is published in the journal Journal of Mammalian Evolution.

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