Study Reveals T. Rex Had a Body Temperature Similar to Humans

How Scientists Measured a Dinosaur’s Internal Heat

Pinning down the exact core temperature of an extinct animal has long frustrated paleontologists. According to Jasmina Wiemann, a paleobiologist at Johns Hopkins University who was not involved in the new research, researchers cannot simply use a thermometer to do that. Previous attempts relied on indirect clues, such as searching for clues in bones or studying how T. rex grew, but those methods failed to yield a firm number.

To overcome this obstacle, the research team analyzed chemical clues preserved within the predator’s tooth enamel. Co-author Aradhna Tripati, a geochemist at the University of California, Los Angeles, explained that atoms inside tooth enamel clump together in different patterns depending on the animal’s body temperature. By examining these patterns across three separate teeth, the research team calculated an average internal temperature of 97 degrees Fahrenheit (36 degrees Celsius).

Comparing T. Rex Body Temperature to Modern Species

The newly calculated temperature places the Tyrannosaurus rex remarkably close to modern mammals. According to the study findings, a T. rex was similar to modern elephants, and not too far from the average human body temperature range of 97 to 99 degrees Fahrenheit (36 to 37 degrees Celsius).

However, the result surprised some researchers who anticipated a higher reading. Jasmina Wiemann noted that she expected the predator to run a few degrees hotter, pointing to modern birds—dinosaurs’ warm-blooded descendants—as a baseline for elevated body temperatures.

Ecological Impact and Future Research

Knowing the exact body temperature allows scientists to model how the prehistoric predator interacted with its environment. According to Aradhna Tripati, a stable internal temperature of 97 degrees Fahrenheit would have allowed the T. rex to live across most of prehistoric North America, maintaining consistent energy levels in both cooler and warmer regions.

Researchers plan to apply the same tooth enamel analysis to other dinosaurs to understand how temperature regulation influenced dinosaur evolution and dominance. Study co-author Robert Eagle, a geobiologist at UCLA, stated that numerous charismatic species remain to be explored using this chemical method, which could ultimately clarify how ancient reptiles managed their energy requirements and hunted prey.