Palaeontologists in Australia have identified a new species of dinosaur, naming it the Australotitan cooperensis and recognising it not only as the largest animal to ever roam the continent but also among the biggest in the world.
Australotitan, or the southern titan, was a long-necked sauropod that is estimated to have reached 25-30 metres in length and 5-6.5 metres in height, making it as long as a basketball court and as high as a two-storey building.
The findings were published in the journal PeerJ on Monday.
“It’s been a long time coming, but we are very proud to showcase Australia’s largest dinosaur species,” said Scott Hocknull, a palaeontologist at the Queensland Museum and a co-author of the study.
“We know it was a plant-eating dinosaur. It had a very long neck and a very long tail and had the look of a typical brachiosaurus. But it was enormous. It was a titanosaurian.”
Nicknamed Cooper, after the nearby creek where it was first found, the dinosaur is estimated to have lived more than 90 million years ago, during the Cretaceous period, and is estimated to have weighed about 67 tonnes. Its fossilised bones were found in 2006 in an area known as the Eromanga Basin in southwest Queensland.
“These are the largest dinosaurs that ever walked on earth and based on the preserved limb size comparisons, this new titanosaur is estimated to be in the top five largest in the world,” said Robyn Mackenzie, the director of the Eromanga Natural History Museum, who first spotted the dinosaur’s remains along with her husband on her family farm in southwest Queensland.
Since excavations for dinosaur fossils began in the Eromanga Basin, two other large sauropods have also been discovered. They are nicknamed George and Zac.
“These dinosaur discoveries have opened a whole new world, not just to our family, but to people throughout Australia,” Mackenzie was quoted as saying by the 9News broadcaster. “It has been the most enriching journey.”
Hocknull said it had been a “very long and painstaking task” to confirm that Cooper was a new species of dinosaur.
“When you have a dinosaur bone that weighs 200 kilograms, you can’t just put in a car and take them to other museums for comparison. So, we used 3D technology to scan the bones, so that I can go compare them in different museums and different collections in Queensland and other places,” he said.
The process took many years, but over that period Hocknell said he and his team “have been able to figure out that not only is it different, but that it is Australia’s largest dinosaur species.”
The palaeontologist said the study found that the Australotitan was most closely related to three other sauropods that lived in Australia during the Cretaceous period – the Wintonotitan and the smaller Diamantinasaurus and Savannasaurus sauropods.
“That means they are one big happy family,” he said.
The new species also share relations with titanosaurians from South America and Asia, said Hocknell, suggesting they may have travelled to the continent from South America via Antarctica during periods of global warmth.
Or, he said, they might have island-hopped across ancient island archipelagos, which would eventually make up the present-day terrains of Southeast Asia and the Philippines.