--- title: Dinosaur Hatch Time Was Similar to Reptiles description: Non-avian dinosaurs took between three and six months to hatch from their eggs, according to a study canonical: https://time.com/4621038/dinosaurs-egg-hatch-three-six-months/ author: Mahita Gajanan article:opinion: false article:content_tier: free article:published_time: 2017-01-03T19:40:11.000Z article:modified_time: 2026-08-04T08:04:20.189Z article:section: Science og:title: Dinosaurs Took Between 3 and 6 Months to Hatch, Study Finds og:description: It may have affected their ability to compete with fast generating populations og:url: https://time.com/4621038/dinosaurs-egg-hatch-three-six-months/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltc5f24f9c1b2f0503/6988b44da988ca2e716ba8b7/dinosaur-embryos-fossil.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: dinosaur-embryos-fossil og:type: article twitter:card: summary_large_image twitter:title: Dinosaurs Took Between 3 and 6 Months to Hatch, Study Finds twitter:description: It may have affected their ability to compete with fast generating populations twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltc5f24f9c1b2f0503/6988b44da988ca2e716ba8b7/dinosaur-embryos-fossil.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # Dinosaurs Took Between 3 and 6 Months to Hatch, Study Finds ## Video: Scientists Have Discovered the First Dinosaur Brain Fossil [Watch (HLS stream): Scientists Have Discovered the First Dinosaur Brain Fossil](https://cdn.jwplayer.com/manifests/NgWf7jx2.m3u8) (0:56)  _Published 2016-10-27. More than a decade ago, an amateur fossil collector found a brown, pebble-sized lump on a beach in Sussex, England. Now scientists have determined that lump is the first known fossilized brain tissue from a dinosaur._ by [Mahita Gajanan](https://time.com/author/mahita-gajanan/) ## Mahita Gajanan Gajanan is an editor at TIME. Jan 3, 2017 7:40 PM UTC  A photo of a hatchling Protoceratops andrewsi fossil from the Gobi Desert Ukhaa Tolgod, Mongolia. A photo of a hatchling Protoceratops andrewsi fossil from the Gobi Desert Ukhaa Tolgod, Mongolia.AMNH/M. Ellison by [Mahita Gajanan](https://time.com/author/mahita-gajanan/) ## Mahita Gajanan Gajanan is an editor at TIME. Jan 3, 2017 7:40 PM UTC Non-avian dinosaurs took between three and six months to hatch from their eggs, according to a study that [examined the teeth of fossilized dinosaur embryos](http://www.amnh.org/about-the-museum/press-center/dinosaur-eggs-took-3-to-6-months-to-hatch). Scientists have long assumed [dinosaur incubation](http://time.com/4596412/dinosaur-tail-feathers-amber/) was similar to the rapid incubation of birds, which hatch within 11 to 85 days. However, the study found that dinosaurs aligned more with the prolonged incubation of reptiles. Growth lines in the teeth of dinosaur embryos showed “slow reptilian-grade development” spanning months, scientists wrote in a study published in [_Proceedings of the National Academy of Sciences_](http://www.pnas.org/content/early/2017/01/01/1613716114.full). The research results suggest that dinosaurs’ slow development may have affected their ability to compete with the more quickly generating populations of birds, reptiles and mammals after the [mass extinction](http://time.com/4581545/asteroid-dinosaurs-liquid-surface/) 65 million years ago. “We know very little about dinosaur embryology, yet it relates to so many aspects of development, life history, and evolution,” study co-author Mark Norell said in a [press release](http://www.amnh.org/about-the-museum/press-center/dinosaur-eggs-took-3-to-6-months-to-hatch). “But with the help of advanced tools like CT scanners and high-resolution microscopy, we’re making discoveries that we couldn’t have imagined 20 years ago. This work is a great example of how new technology and new ideas can be brought to old problems.” ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4621038/dinosaurs-egg-hatch-three-six-months/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4621038/dinosaurs-egg-hatch-three-six-months/"},"headline":"Dinosaurs Took Between 3 and 6 Months to Hatch, Study Finds","datePublished":"2017-01-03T19:40:11.000Z","dateModified":"2026-08-04T08:04:20.189Z","description":"It may have affected their ability to compete with more rapidly generating populations","url":"https://time.com/4621038/dinosaurs-egg-hatch-three-six-months/","keywords":["Paleontology","onetime"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/bltc5f24f9c1b2f0503/6988b44da988ca2e716ba8b7/dinosaur-embryos-fossil.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Mahita Gajanan","jobTitle":"Gajanan is an editor at TIME.","url":"https://time.com/author/mahita-gajanan/"}],"articleSection":"Science","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/bltc5f24f9c1b2f0503/6988b44da988ca2e716ba8b7/dinosaur-embryos-fossil.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"dinosaur-embryos-fossil","caption":"A photo of a hatchling Protoceratops andrewsi fossil from the Gobi Desert Ukhaa Tolgod, Mongolia.","creditText":"AMNH/M. 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