Using fossilized dinosaur eggshells, Cal State Fullerton geologist Sean J. Loyd is among a group of collaborators conducting research focused on the long-standing debate of the body temperatures of dinosaurs and how those temperatures likely reflect their activity levels.
Their research, led by UCLA scientists and published in the journal Nature Communications, examined 70-80 million-year-old fossilized dinosaur eggshells from Argentina and Mongolia. The findings indicate that some dinosaurs could regulate their internal body temperatures, rather than strictly rely on external heat sources in the environment, such as the sun.
The researchers also believe some dinosaurs were probably more active than modern-day cold-blooded animals, such as alligators and crocodiles.
Loyd, assistant professor of geological sciences, said that in many cases geologists rely on geochemical signatures recorded in minerals, including those that constitute eggshells, to determine formation conditions.
“In this case, a novel isotope technique was applied to dinosaur eggshells to calculate the temperatures at which they formed. Since the eggshells form within the bodies of female dinosaurs, the temperatures are directly related to internal body temperatures,” he explained.
His role in the project was to help determine if samples used were geochemically altered. If altered, the temperatures reconstructed by geochemistry may not accurately reflect body temperatures. Researchers found many eggshells exhibited textural and mineralogical characteristics consistent with preservation, and more reflective of body temperatures, he added.
“The most interesting finding is that dinosaurs seem to occupy a range of internal temperatures, likely spanning between purely cold-blooded — exothermic — to purely warm-blooded — endothermic,” Loyd said. “These findings have implications for dinosaur physiology and activity potential.”