Groundbreaking Fossils Reveal Australia’s Own T-Rex and the World’s Oldest Megaraptorid
Scientists have uncovered fossils of terrifying super-predators that once roamed Victoria. These discoveries reveal Australia’s unique dinosaur hierarchy and rewrite the evolutionary history of theropods. The research, led by the Museums Victoria Research Institute and Monash University PhD student Jake Kotevski, found the world’s oldest known megaraptorid and the first evidence of carcharodontosaurs in Australia.
Figure 1: Illustrations of the megaraptorid and carcharodontosaur. (Credit: Jonathan Metzger)
Uncovering Victoria’s Prehistoric Apex Predators
The fossils, discovered along the Bass Coast and Otway Coast, date back 121 million years. They reveal a diverse predator ecosystem dominated by:
- Megaraptorids – large, powerful apex predators measuring 6–7 metres long.
- Carcharodontosaurs – smaller but deadly hunters, ranging from 2–4 metres.
- Unenlagiines (“Southern Raptors”) – agile predators reaching about a metre in length.
“The discovery of carcharodontosaurs in Australia is groundbreaking,” Kotevski said. “It’s fascinating to see how Victoria’s predator hierarchy diverged from South America, where carcharodontosaurs reached Tyrannosaurus rex-like sizes up to 13 metres, towering over megaraptorids. Here, the roles were reversed, highlighting the uniqueness of Australia’s Cretaceous ecosystem.”
The “Hug of Death” – How Megaraptorids Hunted
The megaraptorids, equipped with long claws, killed their prey using a deadly technique—a “hug of death.” This method involved gripping their victims with their massive claws and delivering fatal strikes. Two of the fossils represent the oldest known megaraptorids, offering new insights into their evolutionary history.
“The findings not only expand Australia’s theropod fossil record but offer compelling evidence of faunal interchange between Australia and South America through Antarctica during the Early Cretaceous,” said Dr Thomas Rich, senior curator of vertebrate palaeontology at Museums Victoria Research Institute.
Australia’s Dinosaur Ecosystem Defied Expectations
In South America, carcharodontosaurs ruled as apex predators, reaching sizes comparable to T-Rex. In Australia, however, the roles were reversed. Megaraptorids became the dominant hunters, while carcharodontosaurs remained smaller.
“This discovery challenges previous assumptions about body-size hierarchies in Gondwanan predator ecosystems, highlighting Victoria’s unique Cretaceous fauna,” Rich said.
Fossils Unearthed from Key Sites in Victoria
The research identified five theropod fossils from two major fossil-rich regions:
- Bass Coast (Bunurong/Boonwurrung Country, Upper Strzelecki Group) – 121.4–118 million years ago
- Otway Coast (Eastern Marr Country, Eumeralla Formation) – 113–108 million years ago
Three of these fossils, discovered between 2022 and 2023, were first identified by Museums Victoria volunteer Melissa Lowery. This highlights the significant role of community members in major scientific breakthroughs.
Museum Collections Reveal Hidden Secrets
Tim Ziegler, vertebrate palaeontology collection manager at Museums Victoria Research Institute, emphasised the role of museums in expanding scientific knowledge.
“Museum collections are crucial to advancing our understanding of prehistoric life,” Ziegler said. “Specimens preserved in the State Collection for decades—unidentifiable until now—are providing new insights into the evolution of dinosaur ecosystems.”
The Next Steps in Dinosaur Discovery
Kotevski and his team continue to survey key fossil sites, including locations where the megaraptorid fossils were found. Their work, as part of the Dinosaur Dreaming Project, has already led to over 10,000 fossil discoveries, including:
- At least seven different dinosaurs
- Three groups of mammals
- Birds, pterosaurs, plesiosaurs, turtles, and fish
The research, published in the Journal of Vertebrate Paleontology, marks a significant milestone in understanding Australia’s prehistoric past. It proves that Victoria was once home to some of the most formidable predators of the Cretaceous period.
With more excavations planned, scientists believe this is only the beginning of uncovering Australia’s ancient giants.
