A discovery of dinosaur tracks on Australia’s southern coast — dating back to the Early Cretaceous when Australia was still connected to Antarctica — indicates that large theropod dinosaurs thrived in this polar environment, prowling the river floodplains when the ice thawed during the summers.
The journal Alcheringa published the analyses of the tracks made in the Wonthaggi Formation south of Melbourne between 120 and 128 million years ago. The find includes 18 theropod tracks and four tracks made by ornithopods — small, herbivorous dinosaurs that may have been prey for the theropods.
“These numerous tracks are the best evidence yet that these former polar environments supported large carnivores,” says Anthony Martin, first author of the study and a professor in Emory’s Department of Environmental Sciences. “The large theropods would likely have fed on prey such as smaller dinosaurs, fish and turtles.”
Theropods, from the ancient Greek for “wild beast foot,” are a dinosaur clade characterized by walking on two legs and feet with three clawed toes. They belong to the same evolutionary group as Allosaurus, Tyrannosaurus rex and Velociraptor.
The largest track from the current find was 18.5 inches long. “The hip height of that theropod would have been about the same as the full height of a tall, modern-day human — or a bit more than six feet tall,” Martin says.
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