T. rex had human-like body temperature, fossil teeth reveal warm-blooded predator

Representative Image via Canva For 66 million years, the body temperature of Tyrannosaurus rex (T.rex) lived only in speculation. Now, a new study has taken the dinosaur’s temperature using chemistry locked inside its fossilised teeth, finding an average of about 36.3°C (97.3°F), strikingly close to the human norm. The research, published in Science Advances, offers one of the first direct measurements of an extinct animal’s core temperature and strengthens the case that T. rex was a warm-blooded, high-energy predator capable of thriving across diverse climates, from ancient floodplains to cooler high-latitude regions.A thermometer hidden in tooth enamelThe breakthrough rests on a technique called clumped isotope analysis, which reads temperature signals preserved in the enamel of growing teeth. Inside enamel, rare heavy isotopes of carbon and oxygen form chemical bonds with one another at rates that depend on body heat. Cooler temperatures produce more of these bonds, while warmer temperatures produce fewer. By drilling out a few milligrams of enamel from three T. rex teeth and measuring the abundance of these isotope pairs, researchers could calculate the temperature at which the...