The possibility that “ warm blood '' was flowing in the dinosaur suggests from the fossils of the eggs
by Chris Elt
dinosaurSpeakingTyrannosaurusAndTriceratopsIncludingReptileThere was an image of an animal similar to, but in recent years the theory that it is an ancestor of birds is influential. A new study that analyzed dinosaur eggs has raised the possibility that "dinosaur blood was warmer than reptiles, whose body temperature was more sensitive to outside temperature, and had the ability to maintain a constant body temperature through metabolism."
Eggshell geochemistry reveals ancestral metabolic thermoregulation in Dinosauria | Science Advances
Were dinosaurs warm blooded? Their eggshells say yes | YaleNews
Dinosaur Eggshells Just Added Curious Evidence to a Debate About Their Blood
75-million-year old eggshells suggest most dinosaurs were warm-blooded | New Scientist
In general, mammals and birds that can raise body temperature by metabolismConstant temperature animal”, Reptiles whose body temperature changes with external temperatureClimacteric animal"Is called. However, in recent years, it has been found that the body temperature control of animals is diverse, and it is said that the use of "constant animals" and "variable animals" is no longer scientifically used.
For many years, dinosaurs have been thought to be animals whose body temperature is as sensitive to the external environment as reptiles, but as dinosaurs became more likely to be ancestors of birds, they said, Did he have the ability to raise the value? " However, until recently, there was only indirect method of examining the temperature of ancient creatures, so it seems that detailed research on the temperature of dinosaurs has not been performed.
So I am an American geophysicistRobin DawsonHis research team used a "dinosaur egg shell" to study the temperature of dinosaurs. Researchers used carbonate mineralsOxygen 18WhenCarbon 13By measuring the concentration of the rare radioactive isotope, the temperature at which the mineral was formed is determined. By applying this technique to dinosaur eggs, it is possible to know "how hot the mother dinosaur was when the eggs were formed."
The analysis used a Canadian population about 75 million years agoBirdsofMyasauraWhenTheropodofTroodonLived in Romania about 69 million years agoLower legofTitanosaurusIt is a fossil of a small dinosaur egg.
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Analysis revealed that Myasaura had a body temperature of 44 degrees Celsius, Troodon had a body temperature of 36 to 27 degrees Celsius, and titanosaurus had a body temperature of 36 degrees Celsius. To compare the dinosaur's body temperature with the ambient temperature, the researchers also estimated the temperature of "invertebrate shell fossils" found in the same place as the dinosaur eggs. The body temperature of each of the invertebrates that were compared is easily influenced by the outside, so the shell of the invertebrate reflects the temperature of the surrounding environment.
Comparing the temperature at which the dinosaur eggshell and the invertebrate shell were formed, it was found that both dinosaur eggshells were formed at a higher temperature than the surrounding environment. Myasaura was at least 15 degrees Celsius warmer than the surrounding environment, Titanosaurus was about 3 to 6 degrees Celsius, Troodon was about 10 degrees Celsius, suggesting that warm blood was flowing to both dinosaurs .
An important point of this study is that the dinosaurs analyzed were three major dinosaur groups, each of a different family. It is unlikely that each strain evolved independently to have warm blood, so it is possible that the common ancestors of the dinosaurs had this characteristic. "Our findings suggest that the ability to increase body temperature through metabolism has evolved in early dinosaurs," Dawson says.
The researchers also noted that the size of the dinosaur body was not necessarily related to high body temperature. Dawson argued that feathers could have played a role in insulation during the evolution of theropods.
by Gary Todd