Ice’s Cool! On Dinosaurs Walking on the Poles

How Polar dinosaurs thrived in Australia, and how do we know this was the case

Picture this: You live in an area, and you know that the rocks under your feet formed when your land was closer to the poles. Although the time is perfect for you to find fossil dinosaurs there, you just don’t look because you assume that Polar dinosaurs are just something taken from a random Jurassic World movie.

Then, someone with a sharp eye and lots of patience spots something unusual. Are these dinosaur footprints?! Well, this is a true story, so keep reading!

Recently, I wrote about how the Earth has been changing for the last 1.8 billion years. If you go there, you will see an video recreating where all the continents where relative to the equator during this time.

Off course, it represents such a long time-scale and spatial magnitude that sometimes it’s hard to grasp the implications that this could have on so many other processes. Even well-trained biologists, paleontologists, and geologists struggle some times to visualize the full picture.

However, if you look at the reconstruction closely, you will be able to understand something quite important. Some continents that are now closer to the poles were then closer to the equator. In the same way, areas close to the equator used to be closer to the Poles in the past.

And you may be inclined to think that this ends here, but it doesn’t.

A groundbreaking discovery on Australia’s southern coast is brining us some new information on the dinosaurs that once roamed the Earth,… in polar regions! Yes, you heard that right, in polar regions. But let’s see what do we exactly mean by that.

A team of paleontologists recently uncovered a series of dinosaur tracks in the Wonthaggi Formation, located near Melbourne. These tracks, preserved in sedimentary layers of rocks, offer a rare window into the lives of large theropod dinosaurs and their herbivorous counterparts who lived in the area during the Early Cretaceous, roughly 120 to 128 million years ago.

What makes this find particularly exciting is that it provides the best evidence yet of large carnivorous dinosaurs thriving in polar environments, a part of the world we often think of as inhospitable to life. Or even further, reserved for mammals with well-known adaptations to these extreme climates.

The study, led by Dr. Anthony Martin and published in Alcheringa: An Australasian Journal of Palaeontology, reveals a total of 24 tracks — 18 belonging to theropods and four to ornithopods. As a reminder, theropods were bipedal, carnivorous dinosaurs, such as Tyrannosaurus rex and Velociraptor, while ornithopods were herbivorous, typically bipedal dinosaurs, such as Iguanodon and Parasaurolophus. See the chart below for more information.

While dinosaur bones have been found in the region before, they were often scattered fragments, likely transported by water after the animals had died. These newly discovered tracks, on the other hand, are direct proof that these creatures were alive and walking around in the area.

In other words, these animals were not washed there from other more temperate areas after they died.

So, the Wonthaggi Formation is a fossil-rich site, but most previous discoveries have been of disarticulated bones. However, this changed when Melissa Lowery, a volunteer fossil hunter, noticed the tracks while exploring coastal outcrops during the height of the COVID-19 pandemic. Her dedication and sharp eye led to the identification of 24 tridactyl (three-toed) dinosaur tracks preserved in marine-platform exposures of overbank and floodplain sediments.

After the discovery, the tracks were photographed, measured, and analyzed by the research team using a combination of digital imaging, photogrammetry, and physical molding. This allowed the scientists to study the tracks in detail and compare them to other known dinosaur footprints from similar periods. Then, each track was carefully documented, including its length, width, and any unique characteristics, such as claw marks or deformations in the surrounding sediment.

And do you know what’s the best thing about fossils, and specially tracks? That they can tell us stories about how the animals interacted with the environment, how they moved. And what do these tracks have to say?

The tracks tell a story about life near the South Pole during the Early Cretaceous. The largest theropod (closely related to T. rex) track, at 18.5 inches long, suggests a predator that stood over six feet tall at the hip, comparable in size to modern-day large mammals such as elephants.

And what were they doing there? These theropods were likely hunting smaller dinosaurs and other prey, such as fish and turtles, in what would have been a seasonally frozen landscape. Yes, a seasonally frozen landscape.

But this is where things get interesting. This region was part of Gondwana, the supercontinent that included both Australia and Antarctica. During the Cretaceous, the polar environment experienced long periods of darkness and freezing temperatures, but it also had relatively warm summers, which would have allowed ecosystems to thrive.

The tracks were likely made when dinosaurs walked through wet sand or mud after spring thaws, as the area’s rivers and floodplains began to flow with meltwater.

However, the presence of ornithopod tracks, which were the first discovered in this formation, adds another layer to the story.

These small, herbivorous dinosaurs were likely prey for the larger theropods, but their tracks also suggest that they may have nested in the area and raised their young during the brief polar summers. The ornithopod tracks range in size from four to seven inches, indicating a mix of juveniles and adults.

I mean, how cool is it that some “simple” tracks can tell us so much about the life and reproduction of these animals?

However, one of the most exciting aspects of this discovery is how it challenges the previous assumption that the area was too harsh for large predators to live year-round. On the contrary, the tracks show that not only were dinosaurs present in the region, but they were thriving, with different species coexisting. This paints a picture of a dynamic, rich ecosystem.

The discovery of these tracks is important because it expands our understanding of how dinosaurs adapted to extreme environments, something we didn’t have so much knowledge about before.

Polar regions, with their months of darkness and freezing temperatures, are not typically thought of as dinosaur territory. Yet, the presence of these large theropod and ornithopod tracks suggests that these creatures were not only capable of surviving but perhaps even thriving in these conditions.

“This is the best evidence yet that these former polar environments supported large carnivores,” said Dr. Anthony Martin. The theropods, with their sharp claws and imposing size, likely ruled the landscape, while the smaller ornithopods navigated the floodplains, foraging for food.

Another key takeaway from this study is the role of dedicated researchers and fossil hunters in making these discoveries. Melissa Lowery, for example, found many of the tracks during the pandemic, proving that the scientific process often depends on patience, keen observation, and a little bit of luck.

Her efforts have added valuable data to our understanding of polar dinosaurs, and future studies may reveal even more about how these animals lived.

In the end, these tracks offer us a unique window into a world that was both familiar and alien — dinosaurs walking through what is now Australia’s southern coast, leaving behind footprints that tell stories of life in one of Earth’s most extreme environments. Because, at the end of the day, these lands used to be way closer to the poles.

Oh, the beauty of our dynamic Earth!