Researchers once thought that dinosaurs were sluggish, cold-blooded creatures. Later findings challenged that, suggesting that older dinosaurs were warm-blooded and could control their body temperature.

Most scientists agree that Tyrannosaurus rex was warm-blooded, but pinning down the exact core temperature of an extinct creature is difficult.

“We can’t just use a thermometer to do that,” said Jasmina Wiemann, a paleobiologist at Johns Hopkins University who had no role in the latest work.

Scientists tried other methods like studying how T. rex grew or searching for clues in its bones, but a firm number eluded them.

In a new study, researchers hunted for chemical clues in the fearsome predator’s teeth. It turns out that atoms within the enamel clump together in different patterns based on an animal’s body temperature.

“We figured out how warm the most famous animal of all, a T. rex, was,” said co-author Aradhna Tripati, a geochemist at the University of California, Los Angeles.

Readings from three teeth revealed an average body temperature of about 97 degrees Fahrenheit (36 degrees Celsius). That’s similar to modern elephants and not too far from the average body temperature of humans, which ranges from 97 to 99 degrees Fahrenheit (36 to 37 degrees Celsius).

I didn't know I needed to know this until I did. Now I can imagine myself riding a dinosaur in winter.

Fan edit of Jurassaic Park where everyone has feathers when?

The delusional Big Reptile conspiracy needs to be exposed.

Go away Big Chicken representative

I know you people are causing global warming just to expand your habitat!

This is super cool and I think a nice opportunity to geek out a bit with some relevant knowledge I have:

Warm-bloodedness isn't as simple to split into on/off as most people might think. Both the hyrax and the naked mole rat -- mammals by all accounts -- have limited if any ability to regulate their own body temperatures. Meanwhile, traditionally cold-blooded animals like the great white shark or tuna are capable of producing body heat but just don't regulate their core temperature the same way warm-blooded animals do.

Those larger cold-blooded animals also benefit from being so large that they simply lose less heat because of the square-cube law and are capable of simply retaining body heat for an effective constant elevated temperature. AFAIK that's where science has thought a lot of dinosaurs have fallen for a LONG while, but I think the traditionally warm-blooded hypotheses has been around for a few decades at this point.

IIRC some hibernating mammals also stop thermoregulating while hibernating, so "warm-bloodedness" isn't even continuous across individuals.