Fossil tooth analysis confirms Tyrannosaurus rex was warm-blooded

Key Points:

• A new study published in Science Advances estimates Tyrannosaurus rex's body temperature at about 97°F (36°C), supporting the long-held theory that T. rex was warm-blooded and capable of active metabolism in cold climates.
• Researchers used a novel technique analyzing chemical bonds in fossilized tooth enamel from a T. rex skeleton named Thomas, allowing a direct and precise measurement of body temperature from only tiny samples.
• The estimated temperature places T. rex between modern reptiles and birds, indicating a metabolism more active than cold-blooded reptiles but less than avians, suggesting it could sustain prolonged activity and inhabit a wide range of climates, including Arctic regions.
• This finding implies T. rex required significant food intake to support its metabolism, reinforcing its role as an active predator, and opens new research avenues to apply this method to other dinosaurs and ancient species to better understand the evolution of warm-bloodedness.
• The study enhances understanding of dinosaur physiology and ecology 66-69 million years ago, providing insights into behavior, energy needs, and habitat range, with potential future applications to study the origins of warm-bloodedness in mammals.