Scientists have determined that the Tyrannosaurus rex maintained a body temperature close to that of modern mammals, shedding new light on the physiology of the iconic dinosaur. Through chemical analysis of fossilized T. rex teeth, researchers estimated the predator’s core temperature to be around 36 degrees Celsius, comparable to that of elephants and not far from the average human temperature.
The research, published recently in the journal Science Advances, involved examining the atomic arrangement within the enamel of three T. rex teeth. These patterns, the scientists found, vary predictably according to an animal’s body temperature, allowing the team to infer the dinosaur’s internal heat regulation. This approach offers an innovative method for reconstructing the physiology of extinct species, where direct measurement is impossible.
The notion that dinosaurs, including T. rex, were warm-blooded has been widely accepted in recent decades, challenging the earlier view of these creatures as sluggish, cold-blooded reptiles. However, determining an exact temperature for an extinct animal has remained elusive. Previous attempts involved studying growth rates and bone structure, but these methods did not produce definitive numerical estimates.
“This study gives us a concrete estimate of T. rex’s body temperature based on chemical proxies preserved in teeth,” said Aradhna Tripati, a geochemist at the University of California, Los Angeles, and co-author of the paper. The findings suggest that T. rex had the capacity to maintain a stable internal temperature, which could have allowed it to thrive across varied climates in prehistoric North America.
Jasmina Wiemann, a paleobiologist at Johns Hopkins University not involved in the study, noted that the result was slightly lower than expected. Based on previous research on dinosaur metabolism, she anticipated the T. rex might have had a higher body temperature more akin to modern birds, which are the descendants of theropod dinosaurs.
Understanding the thermal physiology of T. rex is important for reconstructing aspects of its ecology, including hunting behavior and energy requirements. A warm-blooded metabolism would have supported active predation and sustained endurance, helping explain why T. rex was a dominant predator during the Late Cretaceous period.
The researchers emphasized that applying their chemical analysis method to other dinosaur species could further clarify the evolution of thermoregulation among extinct animals. “There are many fascinating species to explore using this technique,” said Robert Eagle, geobiologist at UCLA and co-author. The study’s approach offers new avenues for investigating how body temperature influenced dinosaur biology and ecology.