New Dental Study Reveals T. Rex Body Temperature Was Like an Elephant’s

Decoding the Apex Predator’s Internal Thermostat

Researchers at the University of California, Los Angeles have measured the body temperature of a Tyrannosaurus rex at roughly 36 degrees Celsius by analyzing its fossilized teeth.

Led by Randon J. Flores and Robert A. Eagle, the study provides new empirical data in the long-running scientific debate over dinosaur metabolism and thermal physiology. This internal temperature matches that of a modern elephant.

The Limitations of Bone Histology

Paleontologists have debated dinosaur metabolism for decades.

Researchers previously relied on indirect clues such as bone microstructure, growth rates, and geographic fossil distribution. Some historical studies indicated that many dinosaur species were endotherms capable of generating internal body heat like modern birds and mammals. Others argued that different lineages maintained distinct thermal strategies rather than sharing a single metabolic baseline.

Chemical Bonds in Fossilized Teeth

To bypass limitations inherent in bone histology, the UCLA research team turned to dental thermometry.

By measuring the chemical bonds within the mineralized tissue of T. rex teeth, the geochemists calculated an internal operating temperature of about 36 degrees Celsius. This chemical signature provides a direct reading of the animal’s core body temperature while it was alive.

From Sluggish Reptile to Active Predator

For most of the twentieth century, popular and scientific depictions cast the Tyrannosaurus rex as a sluggish, tail-dragging reptile that relied on ambient solar heat to warm up before moving.

Subsequent discoveries and biomechanical research upended that model, replacing it with the image of an active, bird-like predator popularized by media like the film Jurassic Park.

Managing the Thermal Environment

While researchers widely accept that T. rex was capable of high-energy activity, the physiological mechanism powering that activity remained an open question.

Measuring a 36-degree Celsius body temperature offers concrete physical evidence regarding how the apex predator managed its internal thermal environment.