The team studied fossilized eggs from three distinct dinosaur species that evolved from reptile to bird.
By United with Israel Staff
A team of researchers headed by Hebrew University of Jerusalem Professor Hagit Affek has concluded that dinosaurs regulated their own body temperatures, a question that has gnawed scientists since the first dinosaur fossils were found in 1819. The findings were recently published in Science Advances.
The team developed a novel approach for measuring historical temperatures. By analyzing chemical bonds among heavy isotopes in calcium carbonate minerals, found in eggs, they were able to calculate both the temperature at which minerals formed and the body temperature of the mother that laid the egg. The method is called isotope geochemistry.
The team studied fossilized eggs from three distinct dinosaur species that evolved from reptile to bird. They found that the body temperatures ranged from 35 to 40 degrees Celsius (95-104 degrees Fahrenheit).
This discovery, however did not determine whether dinosaurs were endothermic – able to generate their own body heat – or exothermic – warming up from the sun and the environment.
“The global climate during the dinosaur era was significantly warmer than it is today,” Affek said. “For this reason, measuring only the body temperatures of dinosaurs who lived near the equator wouldn’t tell us whether they were endo- or exothermic because their body temperature may simply have been a cold-blooded response to the hot climates they lived in.”
Dinosaurs from Alberta, Canada, located at a high latitude, were studied to combat this issue. This cold location would help prove that warm body temperatures were internally generated rather than from the climate.
However, with questions of global warming, the team needed to verify the ancient temperature of Alberta in the era of the dinosaurs. Using isotope geochemistry, they studied mollusk shells assumed to have lived along side dinosaurs.
Mollusks are cold-blooded creatures, with a body temperature of 26 degrees Celsius (79 degrees Fahrenheit.) Therefore, they reflect the ambient climate of the time.
With dinosaurs living in Alberta clocking in at a much higher temperature, the scientists showed that the ancient creatures were endothermic.
“We believe that this transformation happened very early on in dinosaurs’ evolution since the Mayasaura eggs—a lizard-like dinosaur species that we tested—were already able to self-regulate their body temperature, just like their warm-blooded, bird-like cousins, the Torrdons,” Affek said.
As the findings were consistent, irrelevant to where the dinosaur species were found, the scientists conclude that they were warm-blooded animals.
The studied specimens seem to be connected to today’s birds, which are warm-blooded.