Researchers at the University of California discovered that Tyrannosaurus rex was warm-blooded

Tyrannosaurus rex had a body temperature of approximately 36 degrees Celsius, similar to that of humans, according to a study published in the journal Science Advances. The discovery provides the first direct chemical evidence that the “king of the dinosaurs” was a warm-blooded animal and changes the perspective on its physiology.

Researchers from the University of California, Los Angeles, analyzed fossilized enamel from two teeth belonging to a T. rex specimen nicknamed “Thomas,” held in the collection of the Natural History Museum of Los Angeles. They measured rare bonds between carbon and oxygen isotopes, formed according to the animal’s internal temperature.

The method became possible after the technology was improved and the amount of fossil required for analysis was reduced by approximately 90%. The researchers used a dental drill to extract just a few milligrams of enamel, then analyzed the sample’s chemical composition with a mass spectrometer.

The estimated temperature is higher than that of today’s cold-blooded reptiles, but lower than that of birds, the evolutionary descendants of dinosaurs. The results support evidence accumulated over recent decades regarding the active lifestyle of many dinosaurs and suggest that T. rex could live in a wide range of environments, including Arctic regions.