ANCHORAGE (AP) -- The success of dinosaurs on land masses near both poles has led an Alaska paleontologist and two Australian colleagues to suggest they may have been warm blooded.
The work of Roland Gangloff, earth sciences curator at the University of Alaska Museum in Fairbanks, and fellow researchers Thomas and Patricia Rich was described Friday in the journal Science.
''These dinosaurs were doing quite well in high latitudes in both hemispheres 110 to 65 million years ago,'' Gangloff said. ''They were exceedingly abundant. Everything we've found says they were in great variety, both herbivore and carnivore.''
That separate dinosaur ecosystems once thrived at latitudes now covered by ice and tundra is just one insight unearthed by two decades of work by scientists working at 13 major sites in Alaska, Australia, Canada, Siberia, New Zealand and Antarctica, according to Gangloff and his co-authors.
The most prolific finds have been dug from eroding permafrost in the west bank of the Colville River and a rugged cove at the base of a 300-foot coastal cliff about 100 miles southeast of Melbourne.
''These studies in southeastern Australia and the North Slope of Alaska have yielded tantalizing glimpses of polar dinosaurs and their habitat,'' wrote Gangloff and Thomas Rich, curator of vertebrate paleontology at the Museum Victoria, and Patricia Vickers-Rich, chair of paleontology at Monash University in Melbourne.
That part of Australia used to be much further south, connected to Antarctica, the American-born Riches describe in their book ''Dinosaurs of Darkness.'' It chronicles how they uncovered new evidence of Australia's polar dinosaurs with the help of an army of volunteers and a tunnel excavated into solid rock.
Building a similar dinosaur mine into the Colville's frozen banks, where summer crews led by Gangloff and others struggle with muck and collapsing banks, could uncover the greatest untapped trove of fossils in the world, Thomas Rich told the Anchorage Daily News in a phone interview from Melbourne.
''I think you guys are sitting on what could be one of the more exciting dinosaur discoveries on Earth, and hardly anyone knows about it,'' he said. ''You've got the potential right there, but what you need is a technology that takes advantage of the permafrost, that doesn't see it as a barrier but as a plus.''
Because polar dinosaurs lived under more extreme conditions than their temperate counterparts, studying them provides scientists with a unique view of prehistoric physiology, the three scientists wrote in Science.
For example, many dinosaurs likely had the capacity to regulate body temperature, just like modern mammals. The annual temperatures on the prehistoric North Slope often resembled modern day coastal Oregon and Washington, Gangloff said.
''On the North Slope, the remains of terrestrial, cold-blooded forms such as lizards and zrocodilians are conspicuous by their absence,'' they wrote in Science. ''These missing components constitute a major part of the more southern fauna, supporting the idea that at least some nonavian dinosaurs were warm-blooded.''
This summer, Gangloff will return for his 14th season on the Colville to excavate skeletons of a whalelike ichthyosaur and a pachyrhinosaur, the most complete horned dinosaur ever found in Alaska. Over the years, he and his team have uncovered about 7,000 bones and teeth plus three kinds of fossilized tracks, providing evidence of 12 prehistoric animal families, he said.
Thousands of the fossils have tumbled from a 100-yard stretch of bluff north of Umiat, where a herd of multi-ton hadrosaurs apparently drowned about 68 million to 70 million years ago. But the fossil-bearing layer runs for more than 60 miles along the west bank, covering the last 40 million years before the dinosaurs went extinct.
''We have to explain why they're so abundant, and why they're where they are, and why they were evolving so rapidly,'' Gangloff said.
For years, Rich and Gangloff have been pushing to find about $300,000 in support to build a permafrost tunnel.
''What I'd like to see is younger people getting involved in it,'' Rich said. ''What I'm thinking is 100 tunnels over the next 50 years ... You have a window of opportunity up there with that oil field and its infrastructure. It's not going to be cheap, but it will never be cheaper.''
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