Scientists have long debated whether the mighty Tyrannosaurus rex was warm‑blooded. New research published in Science Advances provides the first direct temperature estimate, suggesting the dinosaur’s body ran at about 97 °F (36 °C)—a range comparable to modern humans.
How the temperature was measured
The team, led by geobiologist Robert Eagle of UCLA and climate scientist Aradhna Tripati, examined tiny samples of enamel from two teeth of the nearly complete specimen known as “Thomas” at the Natural History Museum of Los Angeles County. By measuring carbon and oxygen isotopes preserved in the enamel, they could infer the temperature at which the tooth formed over 66 million years ago.
“It’s probably the most direct and least complicated constraint on the actual body temperature of a T. rex that’s been possible before,” Eagle said.
Implications for dinosaur biology
The estimated temperature places T. rex well above the typical range for cold‑blooded reptiles (around 82‑86 °F) and within the spectrum of modern warm‑blooded animals. This supports the idea that tyrannosaurs were active predators with high metabolic rates, capable of sustained activity in cooler environments such as the Arctic.
“A warm‑bodied T. rex is a T. rex that can go almost anywhere on the continent, including the Arctic,” Tripati added.
Broader context
Previous evidence—including a 2022 fossilized footprint found in Alaska—hinted that T. rex could thrive in frigid climates. The new temperature data strengthens those conclusions and offers a clearer picture of the dinosaur’s physiology, behavior, and energy needs.
Researchers plan to apply the same isotopic technique to other dinosaurs such as Triceratops, Stegosaurus and Brachiosaurus, which may help resolve long‑standing questions about the metabolic diversity of the dinosaur clade.
Original reporting: WESH Orlando — read the source article.
