Introducing Savannasaurus, a gigantic long-neck dinosaur that lived during the Cretaceous period some 100 million years ago. Its discovery sheds new light on sauropod evolution as well as how these impressive beasts managed to conquer the globe.
The fossilised remains of this dinosaur were discovered in Queensland back in 2005, but it’s taken over a decade for palaeontologists to make sense of the bones. A new study in Scientific Reports shows it to be the most complete sauropod dinosaur skeleton ever found in Australia (sauropods being those iconic long-necked, long-tailed, quadrupedal dinosaurs). Perhaps more importantly, it represents an entirely new kind of dinosaur, one dubbed Savannasaurus elliottorum.
In terms of its physical dimensions, Savannasaurus was big enough to qualify it as a member of the titanosaur family. But among those plus-sized dinosaurs, the Savannasaurus was a middleweight. It had a long neck and a relatively short tail, measuring between 40 to 50 feet (12 to 15 metres) from head to tip of tail. That’s about half the length of a basketball court, but half the length of its distant cousin, Diplodocus.
Skeletal reconstruction of the new dinosaur. (Image: Travis Tischler / © Australian Age of Dinosaurs Museum of Natural History)
But it’s most impressive features were its wide hips and barrel-like ribcage. Savannasaurus’s hips were at least 3 feet (1 meter) wide, making one of the most rotund sauropods ever discovered.
The discovery of Savannasaurus in Australia, along with the recent discovery of another sauropod called Diamantinasaurus, shows that titanosaurs were living worldwide by 100 million years ago. Stephen Poropat, a research associate at the Australian Age of Dinosaurs Museum and lead author of the new study, suggests that the arrangement of the continents and dramatic shifts in climate around the middle part of the Cretaceous Period allowed titanosaurs to spread around the globe.
Back when Savannasaurus was still alive, global average temperatures were warmer than they are today, but it was still quite cool at the poles. This likely restricted the movement of sauropods along the polar latitudes. “We suspect that the ancestor of Savannasaurus was from South America, but that it could not and did not enter Australia until approximately 105 million years ago,” noted study co-author Paul Upchurch in a statement. “At this time global average temperatures increased allowing sauropods to traverse landmasses at polar latitudes.”
This warming period removed the barrier between Antarctica and South America, allowing the sauropods to migrate into Antarctica and eventually into Australia. [Scientific Reports]