Dinosaurs and People
Running Hot and Cold:
The Dinosaur Debate Heats Up
the earliest days of the discovery of dinosaur fossils, it has been
assumed that dinosaurs were cold-blooded. This assumption has been
shaken by recent discoveries to the point of collapse. Several years
ago Jack Horner of the Rocky Mountain Natural History Museum stunned
and angered the paleontoligical world by proposing that dinosaurs
weren't the slow moving, dimwitted, cold-blooded brutes that they had
been presented as for over a hundred years. Based on his study of bone
density, footprints, brain size and other evidence he had come to
believe that dinosaurs were, by and large, warm blooded, quick-witted
At the time his opinions were summarily rejected by most paleontologists and he became a renegade in the dinosaur community. For years he was a lone voice promoting warm-blooded dinosaurs, but the tide began to turn as more scientists studied the evidence. Then last year the final piece of the puzzle was found. A dinosaur heart was discovered and it appeared to have four chambers, a warm-blooded heart, and not a two chambered cold-blooded heart.
There are diehards who are still holding to the cold-blooded model, but most paleontologists have come around to Horner's view. This of course does create another problem, how to classify dinosaurs? You really can't have a warm-blooded reptile. So far this problem hasn't received a lot of attention, though I'm sure it will lead to some very interesting discussions. This whole controversy though is another of those cases where what everybody knew to be true, wasn't. Next time you read or hear that all scientists know evolution to be true, tell it to the dinosaurs.