Scientists have determined the body temperature of T. rex for the first time, and the discovery shows the massive dinosaur ran warmer than the world it lived in. A team of researchers analyzed fossilized teeth from the Hell Creek Formation in Montana and found that Tyrannosaurus rex kept an average body temperature of 36.3 degrees Celsius (97°F).
The findings were published this week in the journal Science Advances. That reading is close to the body temperature of elephants today and only slightly cooler than large flightless birds such as ostriches and emus.
Ancient teeth reveal clues to T. rex’s body temperature
Researchers reached this conclusion by studying a chemical signal called clumped isotopes locked inside tooth enamel from three T. rex specimens.
The method measures how carbon and oxygen atoms bonded together as the enamel formed, revealing the temperature at which it grew inside the animal. Two of the teeth came from a young adult T. rex nicknamed “Thomas,” which weighed more than 3,000 kilograms (6,600 lbs) when it was alive.
To compare T. rex with a cold-blooded animal from the same era, researchers examined teeth from five ancient crocodilians found at the same fossil site.
Those teeth showed an average body temperature of 30.9 degrees Celsius (88°F), several degrees cooler than T. rex. Researchers said the gap points to real differences in how their bodies worked, since both animals lived side by side in the same swampy environment.
T. rex ran hotter than its ancient environment
Researchers also compared the dinosaur’s internal heat with estimates of the surrounding climate at the time. Ancient shellfish from the same region recorded environmental temperatures averaging 25.9 degrees Celsius (79°F), and climate models from the period showed similar readings.
Because the dinosaur ran hotter than both the shellfish data and the modeled climate, researchers concluded it generated much of its own heat instead of absorbing it from its surroundings, a trait linked to warm-blooded animals today.
Researchers called it the most precise measurement of its kind and said it strengthens the case that T. rex was warm-blooded like modern birds and mammals.
Frozen north clues point to T. rex’s wide range
The study’s authors pointed to fossils of young tyrannosaurs found near the Arctic Circle in Alaska, which suggest the animals lived there year-round despite freezing temperatures.
Combining that evidence with the new data, researchers built a model of the climates the dinosaur could tolerate, and the model shows it could have survived across most of North America, including cold northern regions, giving the species a far wider range than previously assumed.
Researchers said the findings support the idea that large meat-eating dinosaurs generated their own body heat rather than depending on the environment to stay active.
See all the latest news from Greece and the world at Greekreporter.com. Contact our newsroom to report an update or send your story, photos and videos. Follow GR on Google News and subscribe here to our daily email!
