GoKawiilIt was once widely believed that dinosaurs were all cold-blooded creatures, since they were classified as reptiles. But there is an increasing amount of evidence to the contrary, though scientists still don’t know the exact body temperatures of most dinosaurs. A domino in that discussion appears to have fallen, with a new study from researchers at UCLA that says the Tyrannosaurus rex had a similar body temperature to humans.
The research, published Wednesday in Science Advances, was done in cooperation with the Natural History Museum of Los Angeles County, which provided teeth from Thomas the T. rex, a 34-foot-tall, 66-million-year-old specimen found in Montana in 2003 and one of the most complete in the world.
Researchers from UCLA measured isotopic signatures on the tooth enamel to determine the giant predator’s body temperature.
According to Robert Eagle, co-author of the study and associate professor at UCLA’s Institute of the Environment and Sustainability, it’s possible to glean information from any bone in the body, but teeth are especially helpful because “tooth enamel has large crystalline structures that are extremely durable,” which helps them resist “chemical alteration” from being underground for eons.
Based on that process, the team determined that the T. rex’s body temperature was likely around 36.3 degrees Celsius (about 97 degrees Fahrenheit).
This puts the T. rex in the same general category as humans with our 98.6-degree bodies. It also puts them in the same neighborhood as Indian and African elephants, as well as large, flightless birds like ostriches and emus.
“This is the first thermodynamically and relatively direct measure of body temperature,” Eagle told CNET in an email.
UCLA created the process years ago and used it to determine that the megalodon was also a warm-blooded predator. However, the method destroys the samples, which led the National History Museum to deny UCLA the teeth until the process could be made more efficient, thereby sacrificing smaller parts of the teeth.
“Nobody hands you a T. rex tooth unless you can show them you only need a few milligrams,” Aradhna Tripati, climate scientist, co-author of the study, and director of the Center for Diverse Leadership in Science, said in an email to CNET. “The instrument and method that my lab did is what made the science possible. It was over a decade of work involving senior scientists, like Rob, and technical staff like the lead author of this study.”
What this tells us about the Tyrannosaurus rex
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