Eggshells support idea that dinosaurs were warm-blooded (earthsky.org)
Posted by Eleanor Imster in Earth | March 4, 2020
Warm-blooded animals (such as mammals and birds) produce their own heat and maintain a constant internal body temperature. Cold-blooded animals (such as reptiles and fish) don’t have internal mechanisms for regulating their body temperature; their body temperature depends on their environment. Where do dinosaurs fit in? Cold-blooded? Warm-blooded? Neither? Those are long-standing questions among scientists, but, so far, no evidence has unquestionably proven what dinosaur metabolisms were like. In February 2020, though, a new research study – an analysis of the chemistry of dinosaur eggshells – provides answers that fall into the warm-blooded camp.
Robin Dawson of University of Massachusetts-Amherst is lead author of the new study, which was published February 14, 2020 in the peer-reviewed journal Science Advances. She said in a statement:
Dinosaurs sit at an evolutionary point between birds, which are warm-blooded, and reptiles, which are cold-blooded. Our results suggest that all major groups of dinosaurs had warmer body temperatures than their environment.
The researchers tested eggshell fossils representing three major dinosaur groups, including ones more closely related to birds and more distantly related to birds.
The testing process is called clumped isotope paleothermometry. It’s based on the fact that the ordering of oxygen and carbon atoms in a fossil eggshell are determined by temperature. Once you know the ordering of those atoms, the researchers said, you can calculate the mother dinosaur’s internal body temperature.
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more: https://earthsky.org/earth/eggshells-suggest-dinosaurs-warm-blooded?
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