Fossil tooth enamel reveals T. rex body temperature near human range
Researchers analyzed isotopes in T. rex tooth enamel from Montana to estimate the dinosaur's internal temperature at about 36 degrees Celsius, similar to modern humans. The method, based on enamel chemistry, offers a more precise metabolic reading than earlier estimates. This supports the view that T. rex was warm-blooded, contrary to older reptilian stereotypes.
The technique relies on measuring isotope ratios in fossilized tooth enamel using a mass spectrometer, a method refined over roughly 15 years. Because enamel forms at a specific temperature and resists environmental contamination, the readings offer a more reliable metabolic snapshot than earlier estimation approaches. The team examined specimens collected in Montana, yielding the 36-degree Celsius figure.
This result aligns with a 2022 study suggesting dinosaurs exhibited varied metabolisms, with T. rex falling on the lower end of warm-bloodedness. The temperature range places T. rex closer to large mammals than to birds, which typically run hotter. Researchers now plan to apply the same enamel analysis to avian dinosaurs and ancient mammalian ancestors, potentially broadening understanding of prehistoric physiology.
This finding could reshape public understanding of dinosaurs, moving them further from cold-blooded reptilian stereotypes toward creatures with mammalian-like physiology. Educators and museum curators may update exhibits and curricula to reflect this precision measurement. The method's success could also spur broader paleontological research, potentially influencing how scientists study ancient life and how the public perceives evolutionary connections between dinosaurs, birds, and mammals.