Scientists unveiled fossils from a new species of giant, long-necked dinosaur unearthed in northeast Australia, speculating that its ancestors had trekked across Antarctica some 105 million years ago.
At least 14 metres from head-to-tail, Savannasaurus elliottorum was a plant-chomping, barrel-chested member of the sauropod group, which includes the largest land animals to ever have roamed the planet.
Wade and Matilda The discovery, along with a specimen of another sauropod called Diamantinasaurus matildae , was detailed in the Nature journal Scientific Reports . Palaeontologists nicknamed the two dinos Wade and Matilda. Both species are thought to be unique to Australia.
How and when these and other dinosaurs made it Down Under is a source of ongoing debate, and the new find is sure to add fuel to the fire.
Some experts say they arrived far earlier than the Cretaceous period, which ended with a cataclysmic bang some 66 million years ago. But the new find points to another scenario, said Stephen Poropat, a scientist at Uppsala University in Sweden and lead author of the study.
“We suggest that our sauropods evolved from South American ancestors,” he said.
These would have crossed a land bridge onto Antarctica, skirted its edge, and then crossed another bridge to Australia.
During most of the Cretaceous period, Mr. Poropat said, the polar continent would have been too cold for these lumbering herbivores to have survived the trip.
But a window opened about 105 million years ago, earlier research has shown, warming the region enough to make a southern passage possible.
“Antarctica was not frozen over, as far as we know, at any time” from 251 to 66 million years ago, he said.
