T rex had body temperature of 36.3°C, almost the same as humans

Tyrannosaurus rex's body temperature was approximately 36.3°C (97.3°F), according to a new study published in Science Advances. Researchers used clumped isotope analysis, a technique that reads temperature signals preserved in tooth enamel, to calculate the dinosaur's core temperature. This method relies on the fact that cooler temperatures produce more chemical bonds of rare heavy isotopes in enamel, while warmer temperatures produce fewer bonds.

The analysis was conducted on three T. rex teeth from a specimen nicknamed Thomas, originally found in Montana. The study suggests that T. rex was a warm-blooded, high-energy predator capable of thriving in various climates, including cooler high-latitude regions. This finding helps explain the predator's ecological dominance and its ability to hunt across vast areas of prehistoric North America.

While some scientists expected a higher temperature, closer to that of modern birds, the new result places T. rex in the same thermal neighborhood as modern humans and elephants, a warm-blooded, or endothermic, range. The study highlights the potential of geochemistry in unlocking new insights about dinosaur physiology and evolution.