Thursday, September 17, 2026
Scientists took a T. rex’s temperature: 97 degrees
Researchers read chemical patterns in the enamel of three fossil teeth to work out how warm Tyrannosaurus rex ran. The answer is about 97 degrees Fahrenheit, close to a human and about the same as an elephant. Most scientists agreed T. rex was warm-blooded but never had a number. The study came out Wednesday in Science Advances.
Scientists found out how warm a T. rex was, and it was about as warm as you. They did it with three of its teeth, which keep a record of body heat like a thermometer you can read a very long time later. Put your hand on your forehead: that’s about how warm a T. rex felt inside. The dinosaurs are long gone, so this one only bites in museums.
Why it worksPut your hand on your forehead. That is the move, and it is why this one lands at five: the dinosaur stops being a picture in a book and becomes a temperature they can feel on their own face. The script ends on museums, because a T. rex that is warm is a T. rex that was alive. Expect that worry.
- “Was T. rex as warm as me?”
- Almost. About 97 degrees, and you are usually 97 to 99. An elephant is about the same.
Also written for and .
Most scientists agree T. rex was warm-blooded, but nobody had a number. Atoms in tooth enamel clump into patterns that depend on body heat, so three fossil teeth worked like a thermometer. The reading: about 97 degrees, close to you.
Why it worksThis is school science with the steps showing: everyone assumed warm-blooded, nobody had checked. Teeth as a thermometer is the part worth slowing down on, because it answers what this age always asks, which is how anybody could possibly know. Expect “how do they know it is right?” Three teeth agreed.
- “How hot was a T. rex inside?”
- About 97 degrees, like you. Scientists read it from atoms in three fossil teeth.
- “Why does it matter how warm it was?”
- A steady temperature let T. rex live across cooler and hotter parts of North America.
Also written for and .
How do you take the temperature of an animal you only know from fossils? For T. rex, you read the atoms in its tooth enamel. Three teeth gave about 97 degrees, and one paleobiologist says she expected hotter, more like a bird. What else could this trick tell us?
Why it worksThe fact is small and the method is not, which is why the script leads with how rather than what. A teenager can follow a technique and then ask what else it could be pointed at, which is the actual scientific move. One paleobiologist expected hotter. The disagreement is in the story, so use it.
- “So it was warm-blooded?”
- Most scientists already thought so. This is the first firm number. One expert expected a few degrees hotter, like a bird.
- “Can they do this for other dinosaurs?”
- The team says that’s next. A co-author says lots of “charismatic species” could be tested the same way.
Also written for and .
Based on the headline: Scientists took a T. rex’s temperature: 97 degrees