for National Geographic News
If famed Norwegian explorer Roald Amundsen trekked across Antarctica a few hundred million years earlier, he may never have returned to reveal the details of the world's underside. Cryolophosaurus ellioti might have eaten him for dinner.
The 22-foot-long (7-meter-long) carnivore with an unusual crest on its skull was one of several dinosaurs that thrived in the extreme polar regions of the world. Though the climate was warmer then than it is now, the dinosaurs endured months of darkness and temperatures that plunged below freezing.
For the last two decades a handful of dinosaur hunters have been chipping fossils from the ice in Antarctica, pulling them from mines dug especially to find the bones in Australia, excavating them from streambeds in New Zealand, and digging them out of frozen riverbanks in Alaska and the cold steppes of Patagonia.
These fossils, skeletal reconstructions, and models and paintings of polar dinosaurs' ancient world went on display in the U.S. last Thursday at the Burke Museum in Seattle, Washington. Cryolophosaurus greets visitors with its teeth bared.
"It's ready to eat you up," said Patricia Vickers-Rich, a paleontologist from Monash University in Australia who is the curator of the "Dinosaur of Darkness" exhibition.
Vickers-Rich is at the forefront of the scientific sleuthing into the dinosaurs that thrived in the polar regions. She's pulled together the fossils and research that are painting a picture of dinosaur life at the top and bottom of the world.
"We are getting a good handle on some parts of the dinosaur ecosystem," said William Hammer, a vertebrate paleontologist at Augustana College in Rock Island, Illinois. Hammer discovered Cryolophosaurus ellioti in Antarctica in 1991. "However, dinosaur finds in Antarctica are rare, so we have a limited amount of data."
Vickers-Rich and her colleague and husband Thomas Rich, a paleontologist at Australia's Museum Victoria museum group, have focused their field research in southern Australia. Australia was deep within the South Pole region during the Cretaceous period (140 to 65 million years ago). The National Geographic Society's Committee for Research and Exploration has supported their research with numerous grants over the past 30 years.
Many of the dinosaurs she and colleagues have found are hypsilophodontids, which were small, speedy, plant-eating dinosaurs that ran on two feet.
"They have huge eyes, and we also know they had large optic lobes in their brain," Vickers-Rich said. This suggests that the dinosaurs had eyesight well adapted to operating during the darkest months of the year.
An analysis of the hypsilophodontids' bone growth indicates that they grew year-round. Such clues are evidence that these herbivores did not hibernate during the coldest and darkest months of the year. They were probably warm-blooded dinosaurs, able to control their body temperature.
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