Cold dinosaurs were just like warm dinosaurs, scientists have found. Species living in the Antarctic, with up to six months of winter darkness, show no major differences in bone structure than those who lived in temperate climates. This was a surprise that falsified earlier studies. Whatever adaptations the high-latitude dinosaurs had did not show up in their bone structure.
Holly Woodward, Montana State doctoral candidate, examined bone tissues from Australian dinosaur fossils that were thought to reside within the Antarctic Circle when the creatures lived. The bones of the dog-sized ornithopods and theropods studied showed annual growth rings, like those of temperate-climate dinosaurs, but no evidence of hibernation. “If we were trying to find evidence of dinosaurs doing something much different physiologically, we would expect it to be found in dinosaurs from an extreme environment such as the South Pole,” she said. “But based on bone tissues, dinosaurs living within the Antarctic Circle were physiologically similar to dinosaurs living everywhere else” (source: PhysOrg). The paper by Woodward and colleagues was published in PLoS One.1
Well-known dinosaur researcher Jack Horner commented, “I think the most important finding is that polar dinosaurs don’t seem to be any different than any other dinosaurs in respect to how their bones grew.” Woodward found a way to credit the unexpected finding to evolution: “This tells us something very interesting; that basically from the very start, early dinosaurs, or even the ancestors of dinosaurs, evolved a physiology that allowed an entire group of animals to successfully exploit a multitude of environmental conditions for millions of years.” See also the 03/29/2004 entry.
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