In the 2002 movie "Ice Age," a trio of Paleolithic mammals attempts an icy trek to return a lost baby. (20th Century Fox)
Dinosaurs living in the intense cold and months-long darkness of the South Pole were once thought to hibernate during the winter months just to survive.
That old theory has been put on ice.
Montana State University graduate student Holly Woodward found that the physiology of dinosaurs living in Australia over 160 million years ago was practically the same as dinosaurs living everywhere else on Earth. During this period, Australia was located in the Antarctic Circle, meaning the dinosaurs that populated the region lived in complete darkness and extreme cold for up to six months at a time.
Now Woodward has opened the door to find out how these dinosaurs made it through the extreme cold.
“This is basically just the first study, there’s so much more to say,” Woodward told FoxNews.com. There have been few studies done on polar dinosaurs, she explained: "People have a hard time getting to Australia to do these studies. The next step for me is to look at the bones more in depth.”
The journey started for Woodward after hearing a lecture from Dr. Thomas Rich, the author of a study regarding polar dinosaurs done in 1998. Rich’s paper discussed the possible ways in which dinosaurs living in Australia survived; he came up with the idea that dinosaurs near the southern pole hibernated during the dark winter months.
The concept peaked Woodward’s curiosity.
“I wanted to see if that hypothesis held true,” Woodward told FoxNews.com. “Because there wasn’t as much dinosaur material back then, I wanted to see if it held up. I spoke with [Dr. Rich] after his presentation, and he told me if I could find a way to get to Australia, I could look at more specimens.”
After applying to the East Asia and Pacific Summer Institute through the National Science Foundation, Woodward received the money she needed to travel to the land down under. While in Australia, she sampled bones from 18 different dinosaurs that lived in the Antarctic circle during the Early Cretaceous Period. The original study had only two bones as samples.
The two studies all hinged on the bones’ “Lines of Arrested Growth” (LAGs) or rings formed inside the bone tissue.
A cross section of a South Pole dinosaur bone. In the center of the bone marrow cavity are dirt and bone matrix. credit: Holly Woodward
“These rings are formed when the bone stops growing,” Woodward told FoxNews.com. The original authors of the study found LAGs in some dinosaur bones and not in others. Since bones don’t grow when an animal hibernates, the absence of rings led them to their original theory. But Woodward’s more extensive sample size showed much different results.
“I found that there were these rings in every specimen except for the smallest. So it actually didn’t have anything to do with hibernating.”
Since the hibernation theory had been the primary theory for how these dinosaurs lived, Woodward inadvertently opened the door for new theories to take its place. She already has a few of her own.
“Maybe these dinosaurs were already adapted from their ancestors to be able to survive in all kinds of conditions. Maybe they had insulation covering them, but you really can’t tell. All we can tell is that their physiology was basically the same as any other dinosaur,” Woodward told FoxNews.com.
Dr. Rich, Anusuya Chinsamy at the University of Cape Town in South Africa, and Patricia Vickers-Rich at Monash Univerty all helped co-author Woodward’s research. Woodward was pleasantly surprised with the ease of the collaboration process -- since these three scientists were the ones who wrote the original study she proved false.
“I just appreciate the openness with which my co-authors have dealt with this,” Woodward told FoxNews.com. “They thought it was cool rather than being upset about it. It’s really easy to get attached to a hypothesis of your own.”
“The fact that they were able to change their world view about these dinosaurs was really great.”
Woodward's paper was published in the journal PLoS ONE on August 3.
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