Victoria’s Dinosaurs

When did they live?

The fossil evidence we have of Victoria’s dinosaurs ranges in age from 105 to 120 million years. All Victorian dinosaur fossils have been recovered from rocks exposed on shore platforms – the only places in Victoria where unweathered rocks of the right age are exposed. Elsewhere, the chemicals involved in soil formation have destroyed any such fossils. For these reasons, future discoveries are unlikely to extend the age range of dinosaurs known from Victoria.

The position of Victoria on the globe during the early Cretaceous.
Source: Dr Thomas Rich, Museum Victoria

What kinds of dinosaurs lived here?

The most abundant and diverse group of dinosaurs in Victoria are the hypsilophodontids, small dinosaurs with long hind limbs, short forelimbs, long tails and a herbivorous diet. They are generally a rare group of dinosaurs in other parts of the world. Three have been named based on Victorian specimens, Atlascopcosaurus, Leaellynasaura and Qantassaurus, and a fourth is present that was first recognised at Lightning Ridge, Fulgurotherium. There are probably at least two more hypsilophodontid genera to be named in Victoria.

While two hypsilophodontid skeletons and many isolated bones and teeth are known from Victoria, the other dinosaur groups found here are represented by just a few fragments of teeth and bone. These fragments hint at the existence of a diverse assemblage of dinosaurs in Victoria. Among these other dinosaur groups are:

• theropods, large carnivorous dinosaurs. The Victorian fossils are from a theropod closely related to the North American Allosaurus.
• an ornithomimiosaur named Timimus (similar to Gallilimus from Mongolia, which was in the dinosaur stampede scene in Jurassic Park).
• a protoceratopsian, Serendipaceratops was a herbivorous dinosaur related to the ancestor of Triceratops.
• an armoured dinosaur related to Minmi, a dinosaur from Queensland, and one of the best known Australian dinosaurs.
• possibly an oviraptorosaur, belonging to a rare group of dinosaurs known only known from a very few skeletons from Mongolia and North America. Oviraptorosaurs had toothless skulls that were short and deep, resembling that of a parrot.

Why are Victoria’s dinosaurs special?

At the time these dinosaurs lived, Victoria was probably much further south, within the Antarctic Circle. At those latitudes there would have been darkness 24 hours a day in the winter months, and constant daylight during summer. Evidence of permafrost (permanently frozen ground) has even been found in Victorian rocks from this time. How dinosaurs survived these conditions is not known. Did they migrate each year, or hibernate, or perhaps they even had a layer of fat as insulation? We do not know.

The dinosaurs from Victoria are a unique mix of old and new dinosaur groups. Some, such as the allosaurs, had died out in other parts of the world long before the Victorian allosaurs existed. Others, such as the ornithomimiosaurs and oviraptorosaurs, have been found only in much younger rocks on other continents.

The fragmentary evidence indicates that Victoria’s dinosaurs are more closely related to the dinosaurs of Asia and North America than they are to those of South America. Because Australia, Antarctica and South America were at that time connected, and distant from Asia and North America, one would expect just the opposite. Why this is so is one of the major puzzles to be solved about Victoria’s dinosaurs.

Map showing the location of early Cretaceous fossil finds in the Otway area of Victoria
source: Lesley Kool

Map showing the location of early Cretaceous fossil finds in the Strzelecki area of Victoria
source: Lesley Kool