| ▲ | T. Rex Had a Body Temperature of 97°F(nytimes.com) |
| 70 points by marojejian 2 days ago | 133 comments |
| gift link:
https://www.nytimes.com/2026/09/16/science/trex-dinosaur-tem... paper:
https://www.science.org/doi/10.1126/sciadv.aeb7653 |
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| ▲ | micromacrofoot 2 days ago | parent | next [-] |
| > Up until the early 2000s, dinosaurs were thought to be rather reptilian and therefore probably coldblooded, Dr. Wiemann said. That began to change as multiple lines of evidence from geochemistry studies and CT scans of fossils showed they were warm-blooded. Dr. Wiemann had previously found that T. rex had a fast metabolism, but she said the new study did an “exquisite” job of zeroing in on a precise body temperature. > To take the body temperature of a long extinct, school-bus-size predator, scientists at the University of California, Los Angeles, used a clever geochemistry technique on fossilized teeth, including two from “Thomas,” a famous T. rex in the collection of the National History Museum of Los Angeles County. fascinating we've also learned more about the air at the time via teeth, https://nautil.us/the-data-in-a-dinos-smile-1229729 |
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| ▲ | SoftTalker 2 days ago | parent [-] | | It intuitively makes sense. A cold-blooded creature of that mass would take a long time to properly warm up or cool down. Most modern cold-blooded animals are small, e.g. frogs, snakes, lizards. They can move into the sunlight or shade as needed and pretty quickly change temperature. |
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| ▲ | code_biologist 2 days ago | parent | prev | next [-] |
| Repost from a different thread: Related only topically, a 1hr YouTube talk I enjoyed a lot: "Hatchling T. rex and the Evolution of Vertebrate Parental Care" by Nick Longrich: https://www.youtube.com/watch?v=zd0dR2n9hLA He's a paleontologist and the talk starts with some pretty interesting statistical analysis aiming to estimate T rex clutch sizes (66 eggs) and hatchling weights (1.5kg) as well as T rex parental care. It ends with looking at evolutionary history trends in increasing parental investment in radically different animals. He talks a little slow, so a little playback speed bump won't go amiss. |
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| ▲ | laweijfmvo 2 days ago | parent | prev | next [-] |
| How do we know its body temperature was 97 degrees, and simply not the environment was 97 degrees? |
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| ▲ | altcognito 2 days ago | parent | next [-] | | They compared against crocodilian teeth and those teeth were at a different temperature. Crocodilian teeth are known to be at a similar temperature to their environment because they are known to be cold blooded. It is correct to say that we don't know they were warm blooded, just that their body temps were likely the given observed temperature. | |
| ▲ | cwmma 2 days ago | parent | prev | next [-] | | If it was environmental then you'd expect it to fluctuate over time, but they also checked it against an animal they knew to be cold blooded, if it was environmental you'd expect them to be the same, but that animal was calculated by the same method to be colder. | |
| ▲ | pixl97 2 days ago | parent | prev | next [-] | | What environment would stay at a constant 97 degrees? | | | |
| ▲ | b0rtb0rt 2 days ago | parent | prev [-] | | [flagged] | | |
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| ▲ | strongwaddle 2 days ago | parent | prev | next [-] |
| 'Hotter than a crocodile,
cooler than a chickennnnn....' is the opening line to a great song i'll never get to hear. |
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| ▲ | ChrisMarshallNY 2 days ago | parent | prev | next [-] |
| Wouldn't be surprised if the smaller raptors had even higher body temps. |
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| ▲ | Obscurity4340 a day ago | parent | next [-] | | I wish raptors could be reanimated and made in miniature so you could have little Raptor domestici (house raptors) running around causing all kinds of hijinks | | |
| ▲ | ChrisMarshallNY a day ago | parent [-] | | I think many of them were about the size of turkeys. Velociraptor was quite small. Jurassic Park used Utahraptor, or Deinonychus as a model. |
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| ▲ | layer8 2 days ago | parent | prev [-] | | Seems sensible, given that birds have higher body temperatures. | | |
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| ▲ | ohyoutravel 2 days ago | parent | prev | next [-] |
| This is really interesting, worth a read. Wouldn’t be surprised if the even larger dinosaurs had even higher body temps! |
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| ▲ | b0rtb0rt 2 days ago | parent | prev | next [-] |
| the best part of this kind of science is that there’s no way to reproduce it or prove if it’s actually true, but it makes a great pop science article |
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| ▲ | SP3269 2 days ago | parent | prev | next [-] |
| I’m missing Marc Bolan. |
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| ▲ | 2 days ago | parent | prev | next [-] |
| [deleted] |
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| ▲ | modzu 2 days ago | parent | prev | next [-] |
| id assumed as much since seeing jurassic park in 1996 |
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| ▲ | lioeters 2 days ago | parent | prev | next [-] |
| From the paper, that is: 36.3 ± 2.5°C. |
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| ▲ | Galilyou 2 days ago | parent | next [-] | | Phew! Thank you! I feel for the ungodly fahrenheit again | | |
| ▲ | nkrisc 2 days ago | parent | next [-] | | I quite like Fahrenheit. The 0 to 100F (-17 to 37C) range perfectly encapsulates the range of outdoor temperatures I expect to encounter during the year. If the forecast is outside that range, it’s going to be miserable. | | |
| ▲ | cosmic_cheese 2 days ago | parent [-] | | Same. I prefer Celsius for most other things but I find Fahrenheit very well suited to climate usage. |
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| ▲ | nmoon 2 days ago | parent | prev [-] | | Fahrenheit is the superior measure | | |
| ▲ | rf15 2 days ago | parent | next [-] | | counterpoint: it doesn't matter, since you need to learn relevant boiling/freezing temperatures on both scales anyway. As a european: F is the only american system that is easy to use and reason with (considering its 0-100 range is spanning the "doable" temp range of too-cold to too-hot), unlike other imperial systems for lengths and whatnot. | | |
| ▲ | t-writescode 2 days ago | parent [-] | | I would argue feet and inches are pretty good too, since there’s a foot on your body, and a thumb, too, for inches. Weight, mass and considerable distances, I’ll grant you, though. | | |
| ▲ | dryrun a day ago | parent [-] | | let me show you the size difference between my wife's thumb and mine, and let's debate again. | | |
| ▲ | t-writescode 21 hours ago | parent [-] | | I feel like you’re intentionally misrepresenting me. I’m obviously talking about number sense, mental visualization, etc. |
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| ▲ | WarmWash 2 days ago | parent | prev | next [-] | | Better for day to day life, worse for science and engineering. | | |
| ▲ | msm_ 2 days ago | parent | next [-] | | Is it really better for day to day life? I am certain that it only appears so because you're used to it. I think for day to day life they're both roughly equivalent. Of course, for me Celsius is more natural and intuitive, but again - that's because I'm used to it. | | |
| ▲ | WarmWash 2 days ago | parent | next [-] | | You can basically put a "%" after a fahrenheit temperature and read it as "percentage of a really hot day" and you'll get a pretty good idea what it feels like outside. It's pretty well calibrated as a 0-100 scale for human temperature perception. | | |
| ▲ | esperent 2 days ago | parent | next [-] | | I moved from a cold climate to a tropical climate and let me assure you there's no human universal understanding of what's comfortably hot or cold, definitely not to the point of putting a percentage on it. I can walk around in a T-shirt and shorts at 17C (62f) while locals will be wrapping up in scarves and talking about how freezing it is. Meanwhile they'll be fairly comfortable at 35C (95f), at least if the humidity isn't high, and I'll be stuck in with the AC blasting. So in other words Fahrenheit is a western centric measurement (or at least, temperature climate centric), while Celsius is universal. | | |
| ▲ | nkrisc 2 days ago | parent | next [-] | | The subjective experience doesn’t really matter because many places in the US will experience a 100 degree F range over an entire year. So it’s not the “comfortable range” but the actual range you’ll get in many parts of the US (whether you like it or not). | |
| ▲ | WarmWash 2 days ago | parent | prev | next [-] | | Right, but "room temperature" is pretty universal everywhere because we are going with the "average human" rather than "outliers exist and maybe feel differently" | | |
| ▲ | esperent a day ago | parent [-] | | No it's not. Room temperature in tropical countries is often 26-30C. I work in the food industry and this whole "room temperature" thing is a major bugbear for me actually because when so much food dates markings are designed around a room temperature of ~22C, it's a big health and safety issue for people (and shops, warehouses, restaurants) who don't know that and happily store the goods up to the date marking at 30C. Deciding that room temperature ~=22C and basing worldwide food safety on that is absolutely Western centric. Obviously people here are not stupid and don't store meat etc. past when it's gone bad. But I've often bought e.g. oils from suppliers and it's clear that it's on the edge of rancidity even though it's got a year+ to go on the date because it's been stored at "room temperature". |
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| ▲ | jandrewrogers 2 days ago | parent | prev [-] | | The US has the widest range of temperatures of any country. Locations can vary by >50°C in a 24 hour period. Extreme temperatures are familiar to Americans and their society is well-adapted to it. Calling Fahrenheit "western centric" is nonsensical. Every other country has a narrower temperature range that fits within the US temperature range. | | |
| ▲ | esperent a day ago | parent | next [-] | | > The US has the widest range of temperatures of any country I assure you it does not. But I guess American Exceptionalism makes you want to believe that so go ahead. A 5s google search suggests the country with the widest range is probably Russia. | |
| ▲ | a day ago | parent | prev [-] | | [deleted] |
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| ▲ | folkrav a day ago | parent | prev | next [-] | | It doesn't map nearly as well for those of us who regularly have temperatures under -17C/0F in the winter. For me Celsius maps a LOT better to the temperatures I actually deal with year round. -17C is, accounting for wind chill, an average-ish winter day, that I'd consider pretty comfortable at this time of the year, assuminv appropriate clothing. | |
| ▲ | konart 2 days ago | parent | prev [-] | | You can do the same thing with celsius if you live in a country with a different temperature "calendar". I'm used to the idea that 0C is what splits the year between cold season and warm season. Obviously people from California will see it differently, for example. So where I live it is like this: 30 or more - hot 15..30 warm 0..15 chilly -15..0 calendar winter -30..-15 real winter ..-30 - freezing, kinds younger than 12 don't go to school | | |
| ▲ | WarmWash 2 days ago | parent [-] | | Sure, but we usually don't judge things on a scale from -30 to +30. Judging anything on a scale from 0-10 (or 0-100) is very common. | | |
| ▲ | konart 2 days ago | parent [-] | | Yes, but that the whole problem: this scale kind of suggests that you don't go below 0. But this is not the case here, right? Some people are used to higher temperatures and never seen snow while some people can't even imagine what it's like to have 40C (104F) outside. 0C is a great "common denominator" (irony). We all understand that generally this is when water changes its state and most people know how it feels. And then your imagination can easily go lower or higher. >Judging anything on a scale from 0-10 (or 0-100) is very common. Now consider that many people live in places where 0F is warmer than what you actually have for a good part of a year. |
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| ▲ | SpecialistK 2 days ago | parent | prev | next [-] | | It's just how some Americans justify this particular measurement system. As you said: it's what you're used to. I know 100F is a very warm day, but if someone said it was 50F I wouldn't intrinsically know how warm or cold that is. My brain works in Celsius, so someone saying its 20C I understand instantly. Similarly length in US football fields - I don't know what that is, but it's second nature to someone who did grow up using them as a measurement. | |
| ▲ | antif 2 days ago | parent | prev [-] | | 100F is about peak summer heat; 0F is about peak winter chills. Works great for describing weather .. in various places. | | |
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| ▲ | jandrewrogers 2 days ago | parent | prev | next [-] | | Kelvin is superior for science and engineering but doesn't arbitrarily anchor the scale to the freezing and boiling point of water in the way Celsius and Fahrenheit both do. 273.15 Kelvin doesn't roll off the tongue like 0°C or 32°F. | | |
| ▲ | vintermann a day ago | parent | next [-] | | It doesn't anchor the scale to water, but it still scales the scale to water since it's still exactly 100 degrees between its boiling point and freezing point. | |
| ▲ | RajT88 2 days ago | parent | prev | next [-] | | 32°F and 212°F roll off the tongue? | | |
| ▲ | jandrewrogers 2 days ago | parent [-] | | Relatively speaking? Yes. Also, the layman rarely needs to know the boiling point of water. The freezing point is useful though. For serious scientific and engineering applications the freezing and boiling point of water isn't actually 0°C and 100°C in most real scenarios. | | |
| ▲ | hibbelig a day ago | parent [-] | | Doesn’t almost everybody cook? With boiling water? | | |
| ▲ | roryirvine a day ago | parent [-] | | Yeah, but you don't need a thermometer for that. Using zero as the freezing point of water makes sense for everyday use, and using the boiling point for 100 degrees does follow fairly naturally from that - but plenty of other potential reference points could have worked equally well. That said, for all the American claims of "fahrenheit is more human", 100 °C is the temperature of a hot sauna so works much better as "the highest temperature you'll encounter in day to day life" than 100 °F. | | |
| ▲ | RajT88 5 hours ago | parent [-] | | > "fahrenheit is more human" This is among the least stupid claims us Americans make in defense of our measurement system. |
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| ▲ | 1718627440 a day ago | parent | prev [-] | | You mean 273.15°K. |
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| ▲ | konart 2 days ago | parent | prev [-] | | >Better for day to day life It is not. |
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| ▲ | deagle50 2 days ago | parent | prev [-] | | really is, and I grew up in celsius. |
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| ▲ | orbital-decay 2 days ago | parent | prev | next [-] | | Thanks, I thought it was almost boiling. | | | |
| ▲ | gibspaulding 2 days ago | parent | prev [-] | | So 97.3 ± 4.5 °F for anyone else curious how the precision translates. |
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| ▲ | verelo 2 days ago | parent | prev | next [-] |
| Please add the measurement system to the title. The times should know better... |
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| ▲ | nkrisc 2 days ago | parent | next [-] | | Well it’s definitely not 97 K, it’s definitely not 97 C, so it’s probably 97 F which would put it in the same general ballpark as nearly all terrestrial vertebrates. | | | |
| ▲ | cr1895 2 days ago | parent | prev | next [-] | | Though it should be pretty obvious from this context that it's not 97 Celsius or Kelvin. | | |
| ▲ | verelo 2 days ago | parent | next [-] | | Sure, but 'F' is a lot shorter than "whichever unit doesn't kill the dinosaur." | | |
| ▲ | articulatepang 2 days ago | parent [-] | | Weird, my browser somehow doesn’t render the title as “T. Rex Had a Body Temperature of 97 Degrees whichever unit doesn’t kill the dinosaur”. It just leaves that last part out, making it even shorter than “F”. | | |
| ▲ | verelo 2 days ago | parent [-] | | "T. rex was warm" is even shorter again. I think we’ve established that omitting information saves space. |
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| ▲ | 2 days ago | parent | prev | next [-] | | [deleted] | |
| ▲ | ray_v 2 days ago | parent | prev [-] | | Unless the Earth was a __VERY__ different place |
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| ▲ | aduwah 2 days ago | parent | prev | next [-] | | I have asked ChatGPT to draw me an image of a 97 degree celsius t-rex and the result was absolutely amazing | | | |
| ▲ | dhdjddhx 2 days ago | parent | prev | next [-] | | It seems that this headline is following the guidelines of the times style guide: "In general, ordinary references to temperature do not specify the scale." | | |
| ▲ | verelo 2 days ago | parent [-] | | Wow is that actually their guideline? | | |
| ▲ | t-writescode 2 days ago | parent [-] | | A random, spare letter wastes space and might have been A/B tested to have a higher click away rate. |
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| ▲ | 2 days ago | parent | prev | next [-] | | [deleted] | |
| ▲ | t-writescode 2 days ago | parent | prev [-] | | The Times is a US magazine. The odds of them picking a US unit of measurement are very high. | | |
| ▲ | verelo 2 days ago | parent | next [-] | | The same newspaper uses Celsius in its climate reporting, including the article below. Apparently the units depend on which extinction we’re discussing. One extra letter would save the guesswork. https://www.nytimes.com/2026/09/02/climate/united-nations-cl... Edit: Removed the headline quotation because the search listing and article heading differ. | | |
| ▲ | t-writescode 2 days ago | parent [-] | | This makes sense from a context and writer perspective. Most conversation about climate change has been around global average temps raising in C. Further, switching that back and forth and doubling it for F would be seen as manipulative by people that don’t want to hear it. On the contrary, the Times’s US audience (probably their main audience) thinks of body temp, which this is, in F. To add further, the audience and writers that want to share cool, new dinosaur fact and the group that does an update on global warming are different people and operate and think differently around these specific things in these specific contexts. Of course it would be easier to add the letter, but I can definitely see why it wasn’t included. | | |
| ▲ | verelo 2 days ago | parent [-] | | That’s a reasonable explanation for choosing Fahrenheit. It’s also a pretty good explanation for choosing to label it, since the same paper uses both scales. | | |
| ▲ | t-writescode 2 days ago | parent [-] | | Indeed. It also turns out, as someone else in this thread has noted, NYT's style guides say to not include the unit in headlines, so here we are :) |
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| ▲ | 2 days ago | parent | prev [-] | | [deleted] |
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| ▲ | mepian 2 days ago | parent | prev | next [-] |
| I read the headline in Celsius and thought that they were a bit too hot. |
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| ▲ | unsnap_biceps 2 days ago | parent [-] | | Would add a new fun dimension to Jurassic Park. "Quick! Climb to 300 meters above sea level and the trex will boil and we will be safe!" | | |
| ▲ | bel8 2 days ago | parent [-] | | to make it even more egregious: "Quick! Climb to about 1000 feet above sea level and the trex will boil and we will be safe!" | | |
| ▲ | dmoy 2 days ago | parent [-] | | I know you were talking about a mountain or something, but "climb to <altitude>" does make one think about this exchange which would be in feet, not meters: "climb to FL20 and the flying dinosaur thing will break" could work though Since, annoyingly, international altitudes are done in increments of 1000 feet (ish, handwaving) |
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| ▲ | john_strinlai 2 days ago | parent | prev | next [-] |
| i know its the nytimes, so we can assume american units, but i find it sort of crazy that even throughout the body of the article it doesnt ever say "fahrenheit". |
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| ▲ | bthrn 2 days ago | parent | next [-] | | Common sense suggests that living creatures are likely not boiling when they have a mild fever. | | |
| ▲ | john_strinlai 2 days ago | parent | next [-] | | i am not a paleontologist and there have been many extremely weird living creatures over the time earth has been around. and as the sibling comment mentions, i am primed for science articles to be metric. | | |
| ▲ | falserum 2 days ago | parent [-] | | I’m metric all the way, but if it would use metric, it still should unambiguously state: C | | |
| ▲ | john_strinlai 2 days ago | parent [-] | | indeed! my "common sense" is to always state the units you're working with, no matter how obvious you think it is. at least, that was the concept was drilled into me throughout all my schooling. perhaps that has changed in the last few decades. |
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| ▲ | SpecialistK 2 days ago | parent | prev | next [-] | | Common sense also suggests using the SI units that ~95% of the planet uses, but here we are. | |
| ▲ | forestry 2 days ago | parent | prev | next [-] | | This is what I told my chemistry teacher in high school when he marked me down for not including units, too. | |
| ▲ | ChrisRR a day ago | parent | prev | next [-] | | I know nothing about dinosaurs, so if you had told me that their blood was 97°C then I would've believed you | |
| ▲ | vojtapol 2 days ago | parent | prev [-] | | Common sense would be using metric units in science-related article. | | |
| ▲ | petcat 2 days ago | parent | next [-] | | Americans don't use Celsius when talking about their body temperatures, and that's who the audience is. | | |
| ▲ | StilesCrisis 2 days ago | parent [-] | | Americans don't use Celsius for anything except scientists talking with other scientists. | | |
| ▲ | ericpruitt 2 days ago | parent | next [-] | | A lot of monitoring software defaults to displaying hardware temperatures in Celsius regardless of the locale, and I've gotten so accustomed to knowing what a reasonable temperature is for different components that I personally never change the display units. | |
| ▲ | d_sem 2 days ago | parent | prev [-] | | that hasn't been my experience. Its widely used in engineering and has been for decades. | | |
| ▲ | wyre 2 days ago | parent [-] | | Ya, I think engineering falls under the umbrella of “scientists talking to other scientists” |
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| ▲ | SoftTalker 2 days ago | parent | prev [-] | | It's a US-based newspaper written for the general public. Common sense would say it's using US units. |
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| ▲ | BugsJustFindMe 2 days ago | parent | prev [-] | | It doesn't need to. Any other unit would be either insanely cold or insanely hot. | | |
| ▲ | skrebbel 2 days ago | parent [-] | | Given that it’s a shouty headline in a major publication, that’s what I would have expected. |
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| ▲ | isomorphic 2 days ago | parent | prev | next [-] |
| https://archive.is/20260916181240/https://www.nytimes.com/20... (Even the NY Times gift link requires a login.) |
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| ▲ | cr1895 2 days ago | parent [-] | | I wonder if that's triggered if NYT determines that a gift link is being widely used? |
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| ▲ | 2 days ago | parent | prev | next [-] |
| [deleted] |
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| ▲ | globular-toast 2 days ago | parent | prev | next [-] |
| Farenheit. So a little bit cooler than us. |
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| ▲ | juancn 2 days ago | parent | prev | next [-] |
| Wow! Close to boiling! /s |
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| ▲ | moomoo11 2 days ago | parent | prev | next [-] |
| i will now believe this information until it becomes outdated in the future, at which point i will believe that information until it becomes outdated later |
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| ▲ | mindcandy 2 days ago | parent | next [-] | | Great! That's how knowledge is supposed to work. | | |
| ▲ | partyficial 2 days ago | parent [-] | | [flagged] | | |
| ▲ | happytoexplain 2 days ago | parent | next [-] | | The word for what you're thinking of is "faith". Theory and belief are the constituents of all consciousness. Young engineers sometimes fall into this trap - that there is absolute truth, and everything else. It would be nice if true, but it's wildly out of line with reality. "Believing" something is not the same as having a dogmatic faith in something. We (ideally) change our beliefs with every new piece of input. That's good. | | |
| ▲ | partyficial a day ago | parent [-] | | > We (ideally) change our beliefs with every new piece of input. That's good. sounds like a cope. like shifting goalposts. or no true scotsman fallacy. if I see a tree in front of me, and 2 seconds later I close my eyes, and someone asks me if there is a tree in front of me, should I say yes because I "know" it, or because I "believe" it ? In that 2 seconds, the tree could have fallen down. So if i said "yes", I wouldn't be lying but I would be incorrect. Therefore all "knowledge" is belief about some past "truth". Whether you call it faith, evidence-based, dogma etc. they all do fall under the same bucket if you think deeply about it. |
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| ▲ | SAI_Peregrinus 2 days ago | parent | prev | next [-] | | No, religion requires faith. Faith is belief without or in direct contradiction of evidence. | |
| ▲ | 2 days ago | parent | prev [-] | | [deleted] |
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| ▲ | ChrisRR a day ago | parent | prev [-] | | It's good to know you've learnt something! |
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| ▲ | ButlerianJihad 2 days ago | parent | prev [-] |
| I can testify that my baseline body temperature (measured sublingually) is 97.6℉ By the way, Google Fit's body-temperature entry is cool, but when it comes to "Location", why is "mouth" in the middle of the list and next to some other, unrelated parts? How is the list being sorted? |
