Ice age kangaroos were more likely to have walked like humans than hopped like… well, kangaroos
The closest living relative to an ice age kangaroo is not a kangaroo at all, but the giant panda
These prehistoric kangaroos were once native to Australia, but now have no evolutionary relatives living on the continent
Kangaroos as we know them today are vastly different to their ancestors. Somewhere between 30,000 and 100,000 years ago, giant kangaroo-like animals, with the faces of rabbits, roamed ice age Australia. There are a number of differences between the modern-day kangaroo we now know and their prehistoric counterparts, and it isn’t just their size.
Lead researcher Christine Janis, a professor of ecology and evolutionary biology at Brown University in Rhode Island, visited numerous museums around the world to study the biology of kangaroos throughout history right up to the present day.
Her findings demonstrated that it’s highly likely the biggest of these ice age ancestors, known as the procoptodon goliah, didn’t hop due to its enormous size. Weighing in at 529 pounds (or 240 kilograms) it’s three times the weight of the kangaroos from present day. That’s a lot of weight to hop around with.
The Ice Age Bi-Ped
Instead, Janis hypothesizes that these gargantuan creatures from the past actually walked around on two legs. After some anatomical study, it was noted that the procoptodon goliah appeared to hold its body upright as opposed to hunched over in any form of hopping position.
In fact, the evidence drawn from their heavy weighted hips, knees, and stabilized ankle joints suggested that they would be perfectly able to support their entire weight on one leg at a time, enabling them to take alternate steps as opposed to jumping to get around.
It’s hard to imagine a kangaroo walking around this way, but then it’s also strange to imagine a kangaroo three times the size as the ones we know, so anything is possible.
Ice Age kangaroos were more like… pandas?
Karen Black, an Australian Research Council postdoctoral fellow of palaeontology at the University of New South Wales in Australia, noted that the anatomical adaptations the procoptodon goliah demonstrates lend themselves more to bipedal movement, just like a human. The thought of a giant kangaroo wandering through ice age Australia is enough to make anyone a little afraid.
Despite the obvious notion that giant ice age kangaroos would naturally be counterparts to the classic Australia kangaroo we know today, it is actually speculated that these gigantic creatures are more akin to the giant panda than they are any Australian inhabitant.
This is due to the heavily reinforced skulls and teeth. Far larger than any modern kangaroo’s, these teeth are assumed to have been built specifically to chew through mature roots, leaves, and branches. This proposed diet is very similar to the diet of the modern panda. Mature roots? Bamboo shoots, anyone?
This ‘roo had bite
It isn’t the procoptodon goliah that most relates to the panda, however. It’s an entirely different ice age kangaroo: the simosthenurus occidentalis. Estimated to have roamed Australia some 42,000 years ago, this edition of ice age kangaroo came equipped with strong cheekbones that would allow for the support of heavy muscle in the jaw. This prevented the jaw from being dislocated when taking strong bites.
In addition to this, the bones around the very front of the skull (where the mouth would be) formed a unique arch that would prevent the jaw from twisting or dislocating when chowing down on whatever ice age delicacy was available to them 50,000 years ago. These characteristics link them to the modern day panda as both animals have a diet of tough foods that require some strong jaw muscles.
Interestingly, the anatomical features of the simosthenurus occidentalis no longer exist in any living herbivore on the Australian continent. This is either a result of evolution due to changing climate circumstances, or they all caught a flight to Asia to live as pandas once the ice age was through. We may never know.
A deeper dive – Related reading on the 101:
No disrespect mama nature, but you’ve created some pretty wild things in your time.
At least you’d see this one coming. Jaws just got outdone.