Dinosaurs weren´t cold-blooded, Depending on whether animals regulate their body temperature
WASHINGTON: Dinosaurs weren´t cold-blooded — like modern-day reptiles — nor were they warm-blooded — like mammals and birds, according to a study out Friday aiming to answer a question that has intrigued paleontologists for decades.
Instead, the prehistoric creatures´ metabolic rates were somewhere in between, said the report published in the US journal Science.
The results suggest that the common practice of splitting species into two distinct groups — depending on whether animals regulate their body temperature externally or internally — is not accurate.
And the answer could help shed light on dinosaur behavior, since warm-blooded animals tend to be more active and grow faster than their cold-blooded counterparts.
To study the metabolism of the long-extinct creatures, a group of researchers led by University of New Mexico biologist John Grady measured annual growth rings in the fossils of several dinosaurs and estimated growth patterns from birth to adulthood.
They compared the results to a baseline of 400 other animal species, both extinct and still alive, and concluded that the dinosaurs´ metabolic rates were somewhere between cold- and warm-blooded animals.