The newly discovered theropod and ornithopod dinosaur footprints date back to the Early Cretaceous period, more than 120 million years ago, when Australia was still connected to Antarctica.
Dinosaur footprints from the Early Cretaceous period have been discovered in the Wonthaggi Formation south of Melbourne, Australia.
These include 18 footprints of medium to large theropods (0.8-1.9 metres waist height) and four footprints of small ornithopod dinosaurs (40-48 centimetres waist height).
“These numerous footprints provide the best evidence yet that polar environments once supported large carnivores,” said Professor Anthony Martin of Emory University.
“Large theropods probably fed on prey such as smaller dinosaurs, fish and turtles.”
“The hip height of this theropod would have been roughly the same as the height of a tall modern human.”
“Rocky coastal strata in Victoria, Australia, mark the spot where the ancient supercontinent Gondwana began to break up about 100 million years ago, separating Australia from Antarctica.”
“The polar environment at that time was a rift valley with a network of rivers running through it.”
“Although the average annual temperature during the Cretaceous period was higher than today, ecosystems experienced freezing temperatures and months of darkness during polar winters.”
“The Wonthaggi Formation has produced one of the best assemblages of polar dinosaur fossils in the Southern Hemisphere, but most of these fossils are small fragments of bone and teeth.”
“These pieces may have been carried to the buried site by heavy spring rains.”
“However, the discovery of so many theropod footprints confirms that a wide variety of dinosaurs did in fact live and walk on the surface where the bones were found.”
“Dinosaur footprints are actually more common here than we previously thought.”
Theropod footprints in the Wonthaggi Formation range in length from 18 to 47 cm (7 to 18.5 in).
They have relatively thin toes and sharp claw tips.
Ornithopod tracks vary in size from 10 to 18 cm (4 to 7 in).
The range of footprint sizes suggests that they may represent a mixture of juvenile and adult ornithopods and theropods.
“This suggests that these dinosaurs may have been nesting and raising their young in polar environments,” Prof Martin said.
This discovery paper of Archealinga, Australian Journal of Palaeontology.
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Anthony J. Martin othersPolar dinosaur footprints from the Wonthaggi Formation (Lower Cretaceous), Victoria, Australia, and their palaeontological significance. Archealinga, Australian Journal of PalaeontologyPublished online September 8, 2024; doi: 10.1080/03115518.2024.2392498
Source: www.sci.news
