October 23, 2007—A trail can hardly get colder than this.
Fossilized tracks recently discovered in southern Australia show that large, meat-eating dinosaurs once roamed near the South Pole a hundred million years ago, scientists say.
The species of dino that made the prints is unknown, said Anthony Martin (pictured), an environmental scientist from Georgia's Emory University who made the find last year.
But judging by the prints, the ancient animal was a two-legged carnivore that stood about 4.6 to 5 feet (1.4 to 1.5 meters) tall at the hip.
"It would've been taller than a fairly tall human," he said. "Its spine would've been above your head."
Martin and colleagues discovered three prints near the coastal town of Inverloch (see map), in an area that had previously yielded fossils of small, plant-eating dinosaurs dating back to when Australia was part of the Antarctic landmass.
But the new find shows that the polar region was also once lush enough to support big, hungry predators.
"It indicates that [large carnivores] had enough to eat, that there was enough biomass in that ecosystem for them to make a living," Martin said. "It's pretty neat to think about."
Just as the Arctic today supports skilled predators like polar bears and grizzlies, Martin said, ancient Antarctica seems to have hosted its share of fearsome hunters.
"The kind of parallel you might have today is if you go up to the north slope of Alaska," he said. "This [new find] may be indicating the same sort of thing [in prehistoric Antarctica]."
Although the South Pole was warmer then than it is now, it was by no means balmy, Martin added. Average temperatures have been estimated around the freezing mark—hardly hospitable to reptiles as we know them today.
"That's why we're rethinking dinosaurs," Martin said. "They weren't like modern reptiles. Some of them were very well adapted, it looks like, to these polar environments."
—Blake de Pastino
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