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Science Frontiers ONLINE No. 75: May-Jun 1991 |
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The Dinosaurs Of Winter And The Polar Forests
It seems appropriate after suggesting above that the dinosaurs might have been frozen to death in a cosmic winter to remind the reader that some of the dinosaurs were pretty tough animals. Many dinosaur fossils have been dug up in Alaska, northern Canada, Siberia, New Zealand, and Antarctica. Not only were some dinosaurs cold-resistant but, seeing many were herbivorous, they were also able to migrate to more temperate climes as the long days of the polar summers waned. The point here is that the dinosaurs as a clan were very adaptable and should have survived severe environmental stress. (Vickers-Rich Patricia, and Rich, Thomas H.; "The Dinosaurs of Winter," Natural History, 100:33, April 1991.)
That the polar regions were once covered by lush forests has been underscored by recent discoveries in both polar regions. Stumps of huge trees 45 million years old dot the now-bleak landscape of Axel Heiberg Island far north of the Arctic Circle. In Antarctica, heaps of 3- million-year-old fossil leaves have been found within 400 kilometers of the South Pole. (Francis, Jane E.; "Arctic Eden," Natural History, 100:57, January 1991. Also: Peterson, Christian; "Leafing through Antarctica's Balmy Past," New Scientist, p. 20, February 9, 1991.)
Comments. Coal beds are also known from Spitzbergen and Antarctica.
The vision of dinosaurs roaming polar Edens evokes many questions. If the polar regions were indeed 10-20�C warmer than now, what could have survived at the Equator? The dates given above (3 and 45 million years ago) for polar heat waves are well after the 65million-year demise of the dinosaurs. This suggests that the biosphere recovered very well from the KTB catastrophe. Why, then did the dinosaurs succomb so completely?