What's happened
Scientists have used tooth enamel chemistry to estimate Tyrannosaurus rex’s body temperature at about 36°C, placing it among warm‑blooded animals. The research, based on clumped isotope thermometry, is published in Science Advances and relies on enamel from three teeth from Hell Creek Formation fossils.
What's behind the headline?
Writing style and context
- This study uses clumped isotope thermometry on dinosaur enamel to estimate body temperature, a method designed to bypass water-content confounds that affected earlier analyses.
- It places T. rex in a warm-blooded spectrum similar to elephants and humans, challenging older cold-blooded assumptions.
- The result prompts questions about how such metabolism affected hunting, energy needs, and geographic range across prehistoric North America.
Implications
- If T. rex ran at ~36°C, it likely maintained a stable internal temperature across diverse environments, enabling broad geographic range and sustained predatory activity.
- The method could be extended to other dinosaurs to map metabolic diversity in the ancient world.
Limits
- The conclusion rests on a small sample from Hell Creek teeth; broader sampling is needed to confirm generality across taxa.
How we got here
The new finding follows decades of debate about dinosaur metabolism. Earlier methods used bone chemistry and growth patterns but yielded uncertain results. Researchers analyzed enamel to avoid diagenetic alteration and compared T. rex teeth with crocodilian teeth from the same ecosystem to contextualize the results.
Our analysis
New data from UCLA geochemists Aradhna Tripati and Robert Eagle, published in Science Advances; corroborating commentary from J. Wiemann (Johns Hopkins) in New York Post and AP News; independent validation discussions in Independent and New York Times Business.
Go deeper
- How does this temperature compare with other dinosaurs?
- What next studies will test enamels from different species?
- Could similar methods reveal temperatures in ancient marine reptiles?
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Science Advances - Peer-reviewed journal
Science Advances is a peer-reviewed multidisciplinary open-access scientific journal established in early 2015 and published by the American Association for the Advancement of Science.
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University of California, Los Angeles - Public university in Los Angeles, California
The University of California, Los Angeles is a public research university in Los Angeles, California. UCLA traces its early origins back to 1882 as the southern branch of the California State Normal School.
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Tyrannosaurus rex - Dinosaur
Tyrannosaurus () is a genus of large theropod dinosaur. The type species Tyrannosaurus rex (rex meaning 'king' in Latin), often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of geological formations which have been dated to the late Maastrichtian age of the late Cretaceous period, 69 to 66 million years ago, with isolated specimens possibly indicating an earlier origin in the middle Campanian age. It was one of the last known members of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, the forelimbs of Tyrannosaurus were short but unusually powerful for their size, and they had two clawed digits. The most complete specimen measures 12.3–12.4 m (40–41 ft) in length, but according to most modern estimates, Tyrannosaurus...
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North America - Continent
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be described as a northern subcontinent of the Americas, or America, in models that use fewer than seven continents.
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Associated Press - News agency company
The Associated Press is an American not-for-profit news agency headquartered in New York City. Founded in 1846, it operates as a cooperative, unincorporated association. Its members are U.S. newspapers and broadcasters.
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