Chapter 1: Understanding Polar Dinosaurs

Imagine living in a region where the rocks beneath you were formed when your land was closer to the poles. You might think of polar dinosaurs as mere fiction from a Jurassic World movie. However, what if I told you that a keen observer recently stumbled upon something remarkable? Could these be dinosaur tracks? Indeed, this is a true account worth exploring!

Recently, I discussed how Earth's geography has transformed over the past 1.8 billion years. A visual representation illustrates where continents were situated relative to the equator throughout this extensive timeline. Grasping the vast time scales and spatial changes can be daunting, even for trained biologists, paleontologists, and geologists.

Upon closer inspection of these reconstructions, it's evident that some continents now near the poles were once situated near the equator. Similarly, areas that are presently equatorial were once positioned closer to the poles.

But there’s more to the story. A groundbreaking discovery along Australia's southern coast has shed light on dinosaurs that thrived in polar regions. Yes, you heard correctly—polar dinosaurs! Let's delve into what this discovery entails.

A group of paleontologists recently discovered dinosaur tracks in the Wonthaggi Formation, located near Melbourne. These tracks, preserved in sedimentary rock layers, provide a rare glimpse into the lives of large theropod dinosaurs and their herbivorous counterparts from the Early Cretaceous, approximately 120 to 128 million years ago.

The video "Walking With Dinosaurs - Episode 5 - Spirits of the Ice Forest Review" discusses how these dinosaurs adapted to their polar environment, offering insights into their behavior and ecology.

What makes this discovery particularly thrilling is that it offers the most compelling evidence thus far of large carnivorous dinosaurs thriving in what we usually consider inhospitable polar climates. The research, led by Dr. Anthony Martin and published in Alcheringa: An Australasian Journal of Palaeontology, reveals a total of 24 tracks—18 from theropods and four from ornithopods. As a reminder, theropods were bipedal, carnivorous dinosaurs, such as Tyrannosaurus rex, while ornithopods included herbivorous dinosaurs like Iguanodon.

Previously, while dinosaur bones had been found in this region, they were often fragmented, likely carried by water post-mortem. However, these new tracks provide direct evidence that these creatures roamed the area alive.

So, the Wonthaggi Formation is indeed a site rich in fossils, but past discoveries primarily featured disarticulated bones. This changed when Melissa Lowery, a volunteer fossil enthusiast, discovered the tracks while exploring coastal formations during the COVID-19 pandemic. Her keen observation 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 meticulously photographed, measured, and analyzed using digital imaging and photogrammetry. This enabled the research team to study the tracks in detail and compare them with other known dinosaur footprints from similar timeframes.

The second video titled "SPIRITS OF THE ICE FORESTS! Walking With Dinosaurs (1999) | Fan Commentary" provides commentary on the significance of these polar dinosaur tracks and how they relate to our understanding of their behaviors.

What’s fascinating about fossils, especially tracks, is their ability to narrate stories about the animals' interactions with their environment. So, what do these tracks reveal? They tell us about life near the South Pole during the Early Cretaceous. The largest theropod track, measuring 18.5 inches, indicates a predator that could have stood over six feet tall at the hip, comparable to modern large mammals like elephants.

What were these predators doing in such an environment? It’s likely they were hunting smaller dinosaurs and other prey such as fish and turtles within a landscape that was seasonally frozen. Yes, a landscape that experienced seasonal freezing!

This area was once part of Gondwana, the supercontinent that included Australia and Antarctica. During the Cretaceous, the polar environment experienced prolonged periods of darkness and freezing temperatures, yet it also had relatively warm summers, allowing ecosystems to flourish.

The tracks were likely formed when dinosaurs traversed wet sand or mud after spring thaws, as rivers and floodplains began flowing with meltwater. The presence of ornithopod tracks, which were the first to be identified in this formation, adds further intrigue. These small herbivorous dinosaurs may have nested in the area and raised their young during the short polar summers, with tracks ranging from four to seven inches, indicating a mix of juveniles and adults.

Isn't it astonishing how something as simple as tracks can provide profound insights into the lives and reproductive behaviors of these creatures?

One of the most exciting aspects of this discovery is how it challenges previous beliefs that the environment was too harsh for large predators to survive year-round. On the contrary, these tracks demonstrate that dinosaurs not only inhabited the region but thrived within a diverse ecosystem.

This discovery significantly enhances our understanding of how dinosaurs adapted to extreme environments, an area previously less explored. Polar regions, typically not associated with dinosaur life, now show evidence that large theropods and ornithopods not only survived but possibly thrived under these conditions.

"This is the best evidence yet that these former polar environments supported large carnivores," Dr. Anthony Martin remarked. The theropods, with their sharp claws and considerable size, likely dominated the landscape, while smaller ornithopods foraged in the floodplains.

Another key takeaway from this study is the invaluable role that dedicated researchers and fossil hunters play in making such discoveries. For instance, Melissa Lowery's efforts during the pandemic have provided critical data that enhances our understanding of polar dinosaurs, and future research may uncover even more about their lifestyles.

Ultimately, these tracks offer a unique insight into a world that is both familiar and foreign—dinosaurs traversing what is now Australia's southern coast, leaving behind footprints that narrate the story of life in one of Earth's most extreme environments. After all, these lands were once much closer to the poles.

Oh, the wonder of our ever-changing Earth!

Published in Fossils et al. Follow to learn more about Paleontology and Evolution.