--- title: Dinosaurs May Have Slept Like Humans, Study Shows description: Reptiles experience the same stages of sleep as humans do, according to a new study, which suggests dinosaurs may have also. canonical: https://time.com/4312291/dinosaur-reptile-sleep-cycle-study/ author: Tessa Berenson article:opinion: false article:content_tier: free article:published_time: 2016-04-29T14:28:29.000Z article:modified_time: 2026-02-22T17:08:37.877Z article:section: Science og:title: Dinosaurs May Have Slept Like Humans, Study Shows og:description: Reptiles cycle through REM sleep too og:url: https://time.com/4312291/dinosaur-reptile-sleep-cycle-study/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt96cc3ffc466d40ef/6988914cab6d7785c46a97cb/bearded-dragon-australia.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 2560 og:image:height: 1440 og:image:alt: 94853023 og:type: article twitter:card: summary_large_image twitter:title: Dinosaurs May Have Slept Like Humans, Study Shows twitter:description: Reptiles cycle through REM sleep too twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt96cc3ffc466d40ef/6988914cab6d7785c46a97cb/bearded-dragon-australia.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Dinosaurs May Have Slept Like Humans, Study Shows > Sponsored content. 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Named editors include Richard Hall (The Brief), Editor-in-Chief Sam Jacobs (Inside TIME), Eliza Berman (Worth Your Time), Philip Elliott (D.C. Brief), Justin Worland (Future Proof) and Harry Booth (In the Loop). Health Matters is written by TIME's health desk. #### How do I sign up for a TIME newsletter? Go to time.com/newsletters, choose the newsletters you want and enter your email address. There is no cost and no subscription requirement.  by [Tessa Berenson](https://time.com/author/tessa-berenson/)  ## Tessa Berenson Apr 29, 2016 2:28 PM UTC  Basking bearded dragon Basking bearded dragon Getty Images  by [Tessa Berenson](https://time.com/author/tessa-berenson/)  ## Tessa Berenson Apr 29, 2016 2:28 PM UTC Reptiles experience the same stages of sleep as humans do, according to a new study, which suggests [dinosaurs ](http://time.com/3629647/dinosaurs-volcanoes-extinction)may have slept like humans as well. [The study](http://science.sciencemag.org/content/352/6285/590), published in the journal _Science_ on Thursday, analyzed results from probes placed in the forebrains of five Australian bearded dragons that monitored the reptiles’ brain activity as they slept. The researchers found that the dragons cycled through REM and slow-wave sleep patterns, just like mammals and birds do (although with different frequency and timing of the cycles). “The results were indeed surprising, because the prevailing view has been that REM and slow-wave sleep are limited to mammals and birds, excluding non-avian reptiles,” Gilles Laurent, co-author of the study, [told the Huffington Post](http://www.huffingtonpost.com/entry/dinosaurs-sleep-reptiles-mammals-lizards-study%5Fus%5F572137c3e4b0f309baefb07d). The results also show that these sleep cycles evolved much earlier than previously thought, possibly back to the emergence of amniotes, the study says. Amniotes are the common ancestor shared by mammals, birds and reptiles and existed about 300 million years ago. 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