An agile, beaked dinosaur that lived on the edge of the Antarctic Circle and may have feasted on pine cones, ferns and even early flowers and fruits has been described from a fossil discovered on the coast of Victoria, a state in Australia’s south-east.
The foot and tail bones of the turkey-sized herbivore, a type of dinosaur known as an ornithopod, were first found on a wave-cut rock platform near Cape Otway, 200 kilometres south-west of Melbourne, on a 2005 fossil dig. After more than a decade of careful preparation and research, they’ve now been named as a new species, Diluvicursor pickeringi, in the journal PeerJ.
The same 2005 dig also turned up the isolated backbone of a carnivorous, fish-eating dinosaur related to North Africa’s Spinosaurus.
“Within minutes of finding that, some toe bones of the new little ornithopod were also found,” says lead author Matthew Herne a palaeontologist at the University of Queensland.
Fossils in these hard, coastal rocks are “difficult to spot and it take a really trained eye, a sixth sense almost, to even notice them,” he adds.
The bones date from 113 million years ago, during the Cretaceous Period, when Australia was further south and still attached to Antarctica in the southern supercontinent of Gondwana.
“It’s really great to see a proliferation of new dinosaurs coming out of Australia in the last few years,” comments Phil Bell a palaeontologist at the University of New England in Armidale, New South Wales.
“It’s finally validating all the work that people have been doing for the last few decades, trying to push Australian palaeontology into the global mainstream.”
The species – which is the first named dinosaur to come out of Victoria since at least 2003 – was found 15 kilometres from the famous Dinosaur Cove site that yielded dinosaurs such as Leaellynasaura, Timimus and Atlascopcosaurus in the 1980s and ‘90s. All four dinosaurs lived near the edge of the Antarctic Circle and would have endured very few hours of daylight – if not complete darkness – in the middle of the austral winter.
Diluvicursor shows that there was a surprising diversity of small grazers here, and suggests there were two body types, says Herne. Leaellynasaura, for example, had a very long tail and was lightly built, while Diluvicursor appears to have been more robust with a much shorter tail. Reconstructions suggest it had strong muscles, making it a powerful runner.
“We don’t know for sure what its diet was, but it could very well have been pine nuts, lichens, mosses, ferns, seeds – and possibly even included flowers and fruit,” says Herne, who adds that fossilised wood found at the site hints at the presence of substantial forests.
There may have been as many as six different small ornithopods in these forests, making it unique globally. “The environment was maybe perfect for a diverse fauna of little herbivorous dinosaurs,” says Herne. “There’s no evidence of large dinosaurs, like sauropods or Muttaburrasaurus here.”
“They were simply the best adapted to the cold environment,” argues Bell, who was not involved in the research. “In equivalent rocks in North America and Asia, these little ornithopods were very rare, and outnumbered by animals similar to Triceratops, or duck-billed hadrosaurs.”
One curious feature of the Diluvicursor specimen is that it had sustained a foot injury, says Stephen Poropat a palaeontologist at the Swinburne University of Technology in Melbourne, Victoria. The injury sustained by this individual “would have been a substantial impediment,” he says. “That the injury healed prior to the animal’s death is interesting and suggests this dinosaur was able to survive despite its ailment.”
Poropat speculates that it may have been able to survive being predated by blood-thirsty theropods long enough for the injury to heal, perhaps because the species lived in herds or sheltered in burrows.
“Time, more fossils and more research, might tell,” he says.
Poropat cautions that because the fossil is a partial skeleton, it can’t directly be compared to related dinosaurs Atlascopcosaurus, Leaellynasaura and Qantassaurus, which were all initially named on the basis of skulls, jaws and teeth.
“It is not impossible that the Diluvicursor skeleton belongs to Atlascopcosaurus,” he says. Only more complete specimens including skull, tail and foot remains will absolutely confirm which skeletons go with which heads, he says.
Diluvicursor pickeringi means Pickering’s flood-runner, and was named after the late David Pickering, a palaeontology collections manager at Museums Victoria. It is one of three new dinosaurs to come out of Australia in the past few years, bringing the total of named species to around 20.