Carnivorous Dinosaurs as Big as T. rex Lived in Jurassic Australia
Paleontologists have analyzed 151- to 165-million-year-old dinosaur footprints from 11 sites in southern Queensland, most of which produced large (length of 30-50 cm) and very large-sized (length greater than 50 cm) theropod dinosaur tracks, including Australia’s largest carnivorous dinosaur footprint (79 cm long).
“I’ve always wondered, where were Australia’s big carnivorous dinosaurs? But I think we’ve found them, right here in Queensland,” said lead author Dr. Anthony Romilio, a paleontologist in the School of Chemistry and Molecular Biosciences at the University of Queensland.
“The specimens of these gigantic dinosaurs were not fossilized bones, which are the sorts of things that are typically housed at museums.”
“Rather, we looked at footprints, which — in Australia — are much more abundant.”
“These tracks were made by dinosaurs walking through the swamp-forests that once occupied much of the landscape of what is now southern Queensland.”
Dr. Romilio and colleagues documented a total of 20 fossil dinosaur tracks and five trackways from the Walloon Coal Measures of Oakey and Rosewood districts in southern Queensland.
They identified a total of 11 track-bearing mines sites (one at Oakey, and ten at Rosewood), and four dinosaur track types.
Large and very large tracks were more common than small tracks. Most of the tracks belong to theropods, the same group of dinosaurs that includes Australovenator, Velociraptor, and their modern-day descendants, birds.
“Most of these footprints are around 50 to 60 cm in length, with some of the really huge tracks measuring nearly 80 cm,” Dr. Romilio said.
“We estimate these tracks were made by large-bodied carnivorous dinosaurs, some of which were up to 3 m high at the hips and probably around 10 m long.”
“To put that into perspective, Tyrannosaurus rex got to about 3.25 m at the hips and attained lengths of 12 to 13 m long, but it didn’t appear until 90 million years after our Queensland giants.”
“The Queensland tracks were probably made by giant carnosaurs — the group that includes Allosaurus.”
“At the time, these were probably some of the largest predatory dinosaurs on the planet.”
The research was published in the journal Historical Biology.
Anthony Romilio et al. Footprints of large theropod dinosaurs in the Middle-UpperJurassic (lower Callovian-lower Tithonian) Walloon Coal Measures of southern Queensland, Australia. Historical Biology, published online June 12, 2020; doi: 10.1080/08912963.2020.1772252