While discovering two new species of dinosaur, paleontologists may have learned how these giants migrated over land bridges between two continents. Two fossil finds in the town of Winton in Central West Queensland, Australia may add credence to what was a popular theory.
Dr. Stephen Poropot, lead researcher and paleontologist from the Australian Age of Dinosaurs Museum, says,
We got a much better idea of the overall fauna. And as a result we can start piecing together how climate affected these dinosaurs, how the positions of the continent affected these dinosaurs and how they evolved through time as well.
Over the span of ten years, researchers have pieced together the skeleton of a new species of dinosaur from 17 pallets of bones encased in rock. They named it Savannasaurus elliottorum, after members of the Elliott family who found the fossil in a pile of bones while tending sheep on their property. In addition, the cranial bones from another new species were also found. It was named Diamantinasaurus matildae.
Dr. Poropot says,
This new Diamantinasaurus specimen has helped fill several gaps in our knowledge of this dinosaur’s skeletal anatomy. This braincase in particular has allowed us to refine Diamantinasaurus’ position on the sauropod family tree.
By plotting the evolution of these sauropods against changes in the positions of the continents, we’ve possibly been able to constrain when these titanosaurs migrated.
Both are sauropods, distinctive for their long necks and small heads. They also had hollow bones with air sacs throughout the body. They are also titanosaurs, some of the largest dinosaurs to ever roam the Earth, at 20 feet tall, weighing around 20 tons. Titanosaurs lived worldwide about 125 million years ago.
Savannasaurus, unlike other sauropods had extra wide hips.
When Savannasaurus was alive in Australia, around 95 million years ago, average global temperatures were warmer than they are now but still cold at the Poles. As the global temperatures increased, the sauropods may have been able to pass over once-frozen land masses between the two continents. They could have entered Australia from South America, across ice-free Antarctica into Australia.
The study states,
High latitude sauropod dispersal might have been facilitated by Albian-Turonian warming that lifted a palaeoclimatic dispersal barrier between Antarctica and South America.
The new fossils suggest that the sauropods in Australia arrived on the continent 100 million years ago, millions of years after the arrival of other species of dinosaur.