The first dinosaurs had metabolisms akin to today’s birds. “Dinosaurs included remarkably swift and agile animals,” says Derek Briggs.
“Dinosaurs included remarkably swift and agile animals with energy levels like those of modern warm-blooded animals and, notably, evolved the exceptional metabolism of modern birds long before active flight,” Derek Briggs says. (Credit: Lucas George Wendt/Unsplash)
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The earliest dinosaurs and pterosaurs had exceptionally high metabolism rates and were warm-blooded animals, researchers report.
The findings in the journal Nature also show that dinosaurs’ metabolism did not decide their fate after an asteroid strike wiped out most animal species on the planet 65 million years ago.
“While modern ecologists tend to emphasize the importance of metabolic rate to ensure that animals survive environmental perturbations, we showed that metabolism is not the reason why birds were the only group of dinosaurs to survive the mass extinction event at the end of the Cretaceous period,” says lead author Jasmina Wiemann, a former Yale University paleontologist who is now at California Institute of Technology. “Many dinosaurs with metabolisms as efficient as those in modern birds went extinct.”
For the study, the researchers identified a new, molecular marker for metabolic stress that can be found in skeletal material in both modern animals and long-extinct species. The biomarker provides paleontologists with the first direct insights into the metabolism of ancient animals.
The metabolic rate reflects how much oxygen an animal breathes, relative to its body mass. As a by-product of oxygen respiration, excess heat is released—which determines whether an animal is warm-blooded and can maintain a constant body temperature or cold-blooded and depends on the outside temperature of their environment for survival.