Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, July 8, 1994 TAG: 9407110187
SECTION: NATIONAL/INTERNATIONAL PAGE: A3 EDITION: METRO
SOURCE: Associated Press
DATELINE: LENGTH: Medium
After analyzing a well-preserved fossil from a 70 million-year-old T. Rex, a research team from North Carolina State University reports in the journal Science that the chemical findings are consistent with bone grown by an animal with a very narrow range of internal temperature.
In modern times, said William J. Showers, leader of the team, such an animal would be called warm-blooded. If this is so, then an animal the size of the 6-to-10-ton T. Rex would have required almost constant feeding, he said, and would be driven by hunger to be an absolutely ruthless hunter.
``Some have called it `the roadrunner from hell,''' said Showers. ``It was the largest land predator ever. If it was warm-blooded, then it was active and eating all of the time.
``It had tremendous teeth and tremendous claws and it looks like it could run very fast,'' he added. A warm-blooded T. Rex, said Showers, ``would be an extremely active animal that could operate at night [when it was cool] and at high latitudes [colder climates]. And it would be a much more voracious predator than animals with a cold-blooded physiology.''
Whether dinosaurs were warm-blooded or cold-blooded has been debated for more than 25 years, and the North Carolina State study has not settled the question, said Mike Parrish, a dinosaur researcher at Northern Illinois University.
Parrish said Thursday that many people still question the validity of tests that measure the chemistry of bone from an animal that died more than 65 million years ago.
``It may not be all that informative'' because of changes caused by water and other natural forces over all of those centuries, he said.
Yale paleontologist John Ostrom, who first suggested that dinosaurs could be warm-blooded, told Science magazine that the North Carolina State conclusions ``are reasonable, but I'm afraid it's still indirect evidence.''
A healthy warm-blooded animal maintains a body temperature within a very narrow range, no matter what the outside temperature is. But a cold-blooded animal is unable to create internal heat and its temperature drops when the weather is cool and rises when it is hot.
For this reason, cold-blooded animals are sluggish and immobile in cold weather and must seek shelter to survive in extremely hot weather. Warm-blooded animals can, within reason, adapt to both conditions.
Thus, if dinosaurs were warm-blooded, it means that they were much more active and more tolerant of climate conditions.
``We've always looked at dinosaurs as dim-witted, slow-moving, cold-blooded reptiles,'' said Showers. But if T. Rex was warm-blooded, he said, then it was fast-moving and endlessly hungry.
by CNB