Dinosaurs may have been less reptilian than scientists once believed; new research shows the ancient beasts may have been warm blooded.
A paper argued dinosaurs would not have been able to exert enough muscle power to attack their prey if they were cold blooded, as is commonly believed, a University of Adelaide press release reported.
"Much can be learned about dinosaurs from fossils but the question of whether dinosaurs were warm-blooded or cold-blooded is still hotly debated among scientists," Professor Roger Seymour, of the University's School of Earth and Environmental Sciences, who wrote the paper, said.
Other scientists disagree with the new findings; they argue there are cold blooded creatures alive today with incredible strength.
"Some point out that a large saltwater crocodile can achieve a body temperature above 30 degrees celsius by basking in the sun, and it can maintain the high temperature overnight simply by being large and slow to change temperature," Seymour said.
"They say that large, cold-blooded dinosaurs could have done the same and enjoyed a warm body temperature without the need to generate the heat in their own cells through burning food energy like warm-blooded animals," he said.
Seymour argues the cold blooded crocodiles can produce only about 14 percent of the muscle power as a mammal, and the percentage drops even more as body size increases.
"The results further show that cold-blooded crocodiles lack not only the absolute power for exercise, but also the endurance, that is evident in warm-blooded mammals," Seymour said.
Seymour's paper concluded dinosaurs would have needed more muscle power than "cold blood" could provide in order to hunt their prey and survive.
"Despite the impression that saltwater crocodiles are extremely powerful animals, a crocodile-like dinosaur could not compete well against a mammal-like dinosaur of the same size," Seymour said. "Dinosaurs dominated over mammals in terrestrial ecosystems throughout the Mesozoic. To do that they must have had more muscular power and greater endurance than a crocodile-like physiology would have allowed."
