‘Dinosaurs killed by cold’

Press, Volume CXII, Issue 32975, 22 July 1972, Page 8

‘Dinosaurs killed by cold’

(N.Z. Press Assn,—Copyright)

LONDON, July 21. The dinosaurs which ruled the earth for a hundred million years were eventually killed by cold, an American scientist says in “Nature”. For, he argues, those giant reptiles were not cold-blooded like modern reptiles. They were warm-blooded, like the advanced animals and birds of today. When a vicious cold snap hit their world of tropical temperatures they died off, just as the large, naked warm-blooded mammals of today, the elephants, rhinos and hippos would if a similar thing happened. As Dr Robert Bakker, of Harvard University’s Museum of Comparative Zoology says, dinosaurs were too big to escape that cold snap—shown in geological records—by burrowing into the ground. The terrible Tyrannosaurus rex, the greatest carnivore that ever lived, and its appetite, provided the basis for Dr Bakker’s theory. The 10-ton Tyrannosaurei, cold-blooded, would not have been quite so menacing to men, if any had lived then,

as science fiction writers have pictured. With a maximum speed of m.p.h., escape from them would have been only a matter of a brisk walk. Dr Bakker’s mathematics prove that cold-blooded Tyrannosaurei could barely have managed 3| m.p.h. Obviously, with their enormous legs, they were built for faster speeds, so must have been warm-blooded to achieve them.

A warm-blooded Tyrannosaurus would have had quite an appetite. To satisfy it, 300 tons to 600 tons of good dinosaur meat would have had to have gone through those jaws each year. Even with the largest dinosaurs helping to slake that appetite Tyrannosaurei must have been rare, otherwise they would have eaten themselves into a famine.

Fossil evidence shows that they were just as rare as Dr Bakker’s calculation has suggested.