T. Rex Teeth Reveal Human-Like Body Temperature

Chemical analysis of fossilized T. rex tooth enamel indicates the dinosaur had a body temperature of about 97°F (36–36.3°C), comparable to humans and elephants. The study, published in Science Advances, provides the first direct temperature estimate and strengthens evidence that T. rex was warm-blooded rather than reliant on external heat like modern reptiles. Researchers measured rare carbon-13 and oxygen-18 isotope bonds that form in enamel at temperature-dependent rates, using samples from three teeth, including teeth associated with the Natural History Museum of Los Angeles County’s specimen Thomas. The findings suggest T. rex could sustain energetic movement and survive in cooler or subtropical climates, though its temperature was lower than that of modern birds. Warm-blooded metabolism would have supported active predation and scavenging but also required greater food intake.