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Dinosaur Bones

August 4, 2011

Holes in fossil bones suggest that dinosaurs were warm-blooded.



A dinosaur bone of contention…I’m Bob Hirshon and this is Science Update.

It was once thought that dinosaurs were cold-blooded and sluggish, like other reptiles. But scientists have been finding evidence that that might not be the case. Roger Seymour is a comparative ecophysiologist at the University of Adelaide in Australia. He and his colleagues measured the size of holes in dinosaur leg bones that served as openings for blood vessels.

ROGER SEYMOUR (University of Adelaide):

And we were surprised – very surprised – to find that the size of the holes in dinosaurs were larger than mammals.


He says the only reason for these holes to be that large would be to accommodate a lot of blood flow. That suggests dinosaurs were active animals — running around and putting stress on their bones — and had the warm-blooded metabolism to match. They plan to look at a variety of other fossil bones to follow up on this preliminary study. I’m Bob Hirshon, for AAAS, the science society.