# Mystery solved: Cutting-edge technology reveals when mammals' ancestors became warm-blooded | Tech News (HT Tech) > Mammals and birds produce their own body heat and control their body temperatures. # Mystery solved: Cutting-edge technology reveals when mammals' ancestors became warm-blooded ## Mammals and birds produce their own body heat and control their body temperatures. Jul 24 2022, 23:58 IST ![Follow on Facebook](https://images.hindustantimes.com/tech/static/revamp/images/png/follow-us-facebook.png) ![Follow on Facebook](https://images.hindustantimes.com/tech/static/revamp/images/png/follow-us-facebook-hover.png) ![Share](https://images.hindustantimes.com/tech/static/revamp/images/png/Share.png) ![Share](https://images.hindustantimes.com/tech/static/revamp/images/png/Shareclicked.png) ![Share on WhatsApp](https://images.hindustantimes.com/tech/static/revamp/images/png/whatsapp.png) ![Share on WhatsApp](https://images.hindustantimes.com/tech/static/revamp/images/png/whatsapp-hover.png) ![Share on Twitter](https://images.hindustantimes.com/tech/static/revamp/images/png/twitter.png) ![Share on Twitter](https://images.hindustantimes.com/tech/static/revamp/images/png/twitter-hover.png) ![Share on Facebook](https://images.hindustantimes.com/tech/static/revamp/images/png/facebook.png) ![Share on Facebook](https://images.hindustantimes.com/tech/static/revamp/images/png/facebook-hover.png) ![Bookmark](https://images.hindustantimes.com/tech/static/revamp/images/png/Bookmark.png) ![Bookmarked](https://images.hindustantimes.com/tech/static/revamp/images/png/Bookmarked.png) ![Mammals](https://images.hindustantimes.com/tech/img/2022/07/24/1600x900/animals-6905640_1280_1658674734402_1658674749057_1658674749057.jpg) Mystery solved: when mammals’ ancestors became warm-blooded (Pixabay) ![Author Photo](https://images.hindustantimes.com/tech/static/revamp/images/png/HTTech-new-circle-logo.png) ### By PTI Mammals and birds produce their own body heat and control their body temperatures. This process is known as endothermy, or warm-bloodedness, and it may be one of the reasons why mammals tend to dominate almost every global ecosystem. Warm-blooded animals are more active during both days and nights than their cold-blooded counterparts and they reproduce faster. But until now it hasn’t been known exactly when endothermy originated in mammalian ancestry. Our new study, just published in Nature, changes that. Also read click here. A combination of scientists’ intuition, fossils from South Africa’s Karoo region and cutting-edge technology has provided the answer: endothermy developed in mammalian ancestors about 233 million years ago during the Late Triassic period. The origin of mammalian endothermy has been one of the great unsolved mysteries of palaeontology. Many different approaches have been used to try to pinpoint the answer but they have often given vague or conflicting results. We think our method shows real promise because it has been validated using a very large number of modern species. It suggests that endothermy evolved at a time when many other features of the mammalian body plan were also falling into place. Warm-bloodedness is the key to what makes mammals what they are today. Endothermy was likely the starting point where mammalness evolved: the acquisition of an insulating fur coat; the evolution of a larger brain, supplied with warmer blood; a faster reproduction rate; and a more active life are all defining mammalian traits that evolved because of warm-bloodedness. Until now, most scientists had speculated that the transition to endothermy was was a gradual, slow process over tens of millions of years beginning near the Permo-Triassic boundary, although some suggested it happened closer to the origin of mammals, about 200 million years ago. In contrast, our results suggest that it appeared in mammalian ancestors some 33 million years prior to the origin of mammals. The new date is consistent with recent findings that many of the traits usually associated with “mammalness”, such as whiskers and fur, also evolved earlier than previously expected. And according to our results, endothermy evolved very quickly in geological terms, in less than a million years. We suggest that the process may have been triggered by novel mammal-like metabolic pathways and the origin of fur. Scientists’ intuition Our research began with Dr Araújo and Dr David’s intuition about the inner ear. It is more than the organ of hearing: it also houses the organ of balance, the semicircular canals. The three semicircular canals of the inner ear are oriented in the three dimensions of space. They’re filled with a fluid that flows in the canals as the head moves and activates receptors to tell the brain the exact three-dimensional position of the head and body. The viscosity, or runniness, of this fluid (called the endolymph) is critical to the balance organ’s ability to efficiently detect head rotation and aid balance. In the same way as a piece of butter turns from solid to liquid in a warm pan, or honey becomes thicker when it is cold, the viscosity of the endolymph changes with body temperature. That means the endolymph’s viscosity would normally be altered by the evolution of a higher body temperature. But the body has to adapt because changing viscosity would prevent the semicircular canals from working properly. In mammals, the canals adapt to higher body temperature by changing their geometry. The researchers realised that this change in the semicircular canals’ shape would be easy to trace through geological time using fossils. Pinpointing the species in which the change of geometry occurred would, they reasoned, provide an accurate guide to when endothermy evolved. They needed fossils to test their hypothesis – and that’s where South Africa’s wealth of fossils from the Karoo region came in. Reconstruction and study The arid Karoo region preserves a treasure trove of fossils, many of them belonging to mammalian ancestors. These fossils offer an unbroken record of the evolution of life over a period of almost 100 million years. They document the transformation from reptilian-like animals (therapsids) to mammals in exquisite detail. Using cutting edge CT-scanning techniques and 3D modelling, we were able to reconstruct the inner ear of dozens of mammalian ancestors from the South African Karoo and elsewhere in the world. From there we could point out exactly which species had an inner ear anatomy consistent with a warmer body temperature, and which ones did not. One thing we had to take into consideration was the geographical position of the Karoo at the time when these animals lived. It was situated closer to the South Pole than it is now as a result of continental drift. That means the warmer body temperature suggested by the geometry of the inner ear cannot be due to an overall warmer climate. As the South African climate was colder on average, the change in inner ear fluid viscosity can only have been caused by a generally warmer body temperature in mammalian ancestors. An exciting time This is an exciting time for our field. Until now, to reconstruct the evolution of endothermy, scientists only had access to skeletal features that questionably correlated with warm-bloodedness. Every attempt was a long shot to get any accurate results. The inner ear, as this research shows, changes this. We believe it may be the key to unlocking more knowledge about mammalian ancestors in future. (The Conversation) By Julien Benoit, University of the Witwatersrand, Kenneth D. Angielczyk, University of Chicago, Ricardo Miguel Nóbrega Araújo, Universidade de Lisboa, and Romain David, Natural History Museum Catch all the Latest Tech News, Mobile News, Laptop News, Gaming news, Wearables News , How To News, also keep up with us on Whatsapp channel,Twitter, Facebook, Google News, and Instagram. For our latest videos, subscribe to our YouTube channel. 24 Jul, 23:58 IST life ![HT Tech Awards](https://tech.hindustantimes.com/ht-tech-power-list-awards-2026/httech-awards-banner-new.webp) ### Related Stories 07 Oct 2026 71,658,665,981,679 NEXT ARTICLE BEGINS ![View all](https://images.hindustantimes.com/tech/static/revamp/images/png/view-all-icon.png) ## Tips & Tricks ![Ghibli-style art](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### How to turn your photos into Ghibli-style art with ChatGPT for free: Step-by-step guide ![How to create an invitation using iPhone’s new Apple Invites app- Step-by-step guide](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### How to create an invitation using iPhone’s new Apple Invites app- Step-by-step guide ![Apple TV app arrives on Android phones and tablets: What you get and how to install it](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Apple TV app arrives on Android phones and tablets: What you get and how to install it ![Vodafone Idea OTT plans](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Vodafone Idea users can now stream 17 OTT apps with one subscription: Here's how ![Android data transfer methods](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### How to transfer data from one Android to another using Google backup, USB-C cable, and more ## Editor’s Pick ![iPhone 16e launched with A18 chip, Apple AI—bringing flagship power on a budget: Check specs, price](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### iPhone 16e launched in India: All details about the new budget mobile from Apple ![DeepSeek was founded in China with only a fraction of the budget of the top AI companies in the US.](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### DeepSeek AI: How it works, who’s behind it, how it’s different from ChatGPT, and its big US market impact explained ![iPhone 17 Air likely to get this feature that iPhone 17 Pro models may miss out on](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### iPhone 17 Air likely to get this feature that iPhone 17 Pro models may miss out on ![Google Whisk AI explained: How remixing works, availability, and how it differs from Gemini](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Google Whisk AI explained: How remixing works, availability, and how it differs from Gemini ![iOS 18.4 beta arriving soon: Know why it is the biggest iPhone update](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### iOS 18.4 beta arriving soon: Know why it is the biggest iPhone update ## Trending Stories ![Airtel 5G SIM card will now be delivered in 10 minutes with Blinkit- How to order](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Airtel 5G SIM card will now be delivered in 10 minutes with Blinkit- How to order ![Infinix Note 50s 5G+](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Infinix Note 50s 5G+ set to launch in India with 64MP camera and MediaTek Dimensity 7300 SoC ![Xiaomi X Pro QLED Series sale starts in India: Check price, availability, and more](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Xiaomi X Pro QLED Series sale starts in India: Check price, availability, and more ![Apple Intelligence AI training](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Apple plans to train AI using your on-device data without accessing personal content or emails: Report ![CMF Buds 2](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### CMF Buds 2 key features and price revealed ahead of April 28 launch: Details inside keep up with tech ![Facebook](https://images.hindustantimes.com/tech/static/revamp/images/png/tech-facebook.png) ![Twitter](https://images.hindustantimes.com/tech/static/revamp/images/png/tech-twitter.png) ![WhatsApp](https://images.hindustantimes.com/tech/static/revamp/images/png/tech-whatsApp.png) ![Facebook](https://images.hindustantimes.com/tech/static/revamp/images/png/tech-facebook.png) ## Gaming ![Check out these five gaming monitors under ₹20,000,](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Top 5 gaming monitors under ₹20000 you should consider ![gaming consoles](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Grab gaming consoles at discounted rates during Amazon Great Indian Festival: Up to 72% off ![Pokémon GO Wild Area 2025](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Pokémon GO Wild Area 2025 to bring Grimmsnarl family, Shiny Hatenna, and global challenges ![Shade Silver](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Shade Silver free on Steam for a limited time: Here’s how to get it ![Call of duty](https://images.hindustantimes.com/tech/static/revamp/images/png/ht-tech-bg-img-90-66.png) ### Call of Duty: Black Ops 7 skips Switch 2 at launch, release date and price leak ![View all](https://images.hindustantimes.com/tech/static/revamp/images/png/view-all-icon.png) ## Trending News ### Airtel 5G SIM card will now be delivered in 10 minutes with Blinkit- How to order ![Airtel 5G SIM card will now be delivered in 10 minutes with Blinkit- How to order](https://images.livemint.com/static/static/1x1_img.gif) ### Infinix Note 50s 5G+ set to launch in India with 64MP camera and MediaTek Dimensity 7300 SoC ![Infinix Note 50s 5G+](https://images.livemint.com/static/static/1x1_img.gif) ### Xiaomi X Pro QLED Series sale starts in India: Check price, availability, and more ![Xiaomi X Pro QLED Series sale starts in India: Check price, availability, and more](https://images.livemint.com/static/static/1x1_img.gif) ### Apple plans to train AI using your on-device data without accessing personal content or emails: Report ![Apple Intelligence AI training](https://images.livemint.com/static/static/1x1_img.gif) ### CMF Buds 2 key features and price revealed ahead of April 28 launch: Details inside ![CMF Buds 2](https://images.livemint.com/static/static/1x1_img.gif) ## Trending Gadgets Mobiles Laptops Tablets ![HT Tech](https://images.hindustantimes.com/tech/static/revamp/images/png/HT_tech-new.gif) - https://tech.hindustantimes.com/tech/news/mystery-solved-cutting-edge-technology-reveals-when-mammals-ancestors-became-warmblooded-71658665981679.html