Researchers from UCLA measured isotopic signatures on the tooth enamel to determine the giant predator\u2019s body temperature.<\/p>\n
According to Robert Eagle, co-author of the study and associate professor at UCLA\u2019s Institute of the Environment and Sustainability, it\u2019s possible to glean information from any bone in the body, but teeth are especially helpful because \u201ctooth enamel has large crystalline structures that are extremely durable,\u201d which helps them resist \u201cchemical alteration\u201d from being underground for eons.\u00a0<\/p>\n
Based on that process, the team determined that the T. rex\u2019s body temperature was likely around 36.3 degrees Celsius (about 97 degrees Fahrenheit).\u00a0<\/p>\n
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.\u00a0<\/p>\n
\u201cThis is the first thermodynamically and relatively direct measure of body temperature,\u201d Eagle told CNET in an email. <\/p>\n
UCLA created the process years ago and used it to determine that the megalodon was also a warm-blooded predator<\/a>. 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.\u00a0<\/p>\n \u201cNobody hands you a T. rex tooth unless you can show them you only need a few milligrams,\u201d 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. \u201cThe 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.\u201d<\/p>\n What this tells us about the Tyrannosaurus rex<\/p>\n This sounds like a simple little thing, but it actually has some rather large implications. A prior study from 2022<\/a> suggested that, while reptiles are cold-blooded, evidence supported the idea that meat-eating dinosaurs had avian metabolisms, which would make them warm-blooded, whereas others, like the plant-eating Stegosaurus, were possibly cold-blooded.\u00a0<\/p>\n \u201cIt\u2019s thought that many dinosaurs, but not necessarily all, were warm-blooded,\u201d Eagle said. \u201cHowever, even amongst warm-blooded (or endothermic) organisms there are questions of the degree \u2014 they can be warm-blooded like sloths or anteaters (low-level endothermy), modern large mammals, or avian endotherms, which typically have higher metabolic rates than mammals.\u201d<\/p>\n At the time, researchers could only guess at the general temperature of many of these dinosaurs, so the study by UCLA not only backs up that the T. rex was warm-blooded, but it\u2019s the first such study to produce precise measurements.\u00a0<\/p>\n \u201cFor an animal this famous, it is remarkable how little we actually knew,\u201d Tripati said. \u201cWe had constraints on T. rex metabolism, mainly from bone and biomechanics, some of which has been controversial. We did not have a direct body temperature determination.\u201d<\/p>\n Figuring out the core body temperature of the T. rex can give scientists all sorts of data about how they behaved and where they lived, and help explain some things humans already knew. For example, Tripati says that T. rex fossils have been found all the way up in Alberta and Saskatchewan and all the way down to Texas. No reptile alive today has that kind of range since they are cold-blooded and need to stick to warmer climates.\u00a0<\/p>\n \u201cThermal physiology drives behavior, range, energy budget and how a species responds to a changing climate,\u201d Tripati said. \u201cA warm-blooded T. rex could have gone almost anywhere on the continent, including the high Arctic. That is a very different animal from a sun-basking reptile.\u201d<\/p>\n Eagle added that being warm-blooded means the T. rex likely had to hunt more often than originally thought to maintain its energy \u2014 and said it\u2019s even possible that the T. rex migrated to find food, which may have led it into colder climates.<\/p>\n \t\t\t\t\t\t\t \t\t\t\t\t\t\t\t\t\t\tJoe is a freelance journalist. It all started with a long-running affection for building his own PCs, which he did for the first time as a teenager. It evolved into a lifelong enjoyment of putting words on the internet about the subject. He’s written for CNET, PCMag, Mashable and SlashGear as a freelance writer, and worked as a Senior Editor at Android Authority for 10 years. When he’s not writing about tech and science, he’s learning the ins and outs of DIY home repair, gaming, playing his bass guitars and posting help on PC building and gaming subreddits. He is a staunch believer that orange juice should have pulp.![\"A](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/09\/Thomas-the-T-Rex.jpg\")
Thomas the T. rex, one of the most complete T. rex specimens in the world, on display at the Natural History Museum of Los Angeles, donated parts of three teeth for UCLA\u2019s research.Zissoudisctrucker\/Wikimedia<\/a><\/p>\n![\"Joe](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/09\/1789609334_551_f6daf44a-3954-4d2e-be68-837ce2953e1f.jpg\")
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