--- title: Scientists Discover First Sex Act description: Ancient fish were the first to copulate. And according to a world renowned paleontologist, it looked a lot like square dancing canonical: https://time.com/3528344/scientists-fish-sex-square-dance/ author: Laura Stampler article:opinion: false article:content_tier: free article:published_time: 2014-10-21T14:18:49.000Z article:modified_time: 2026-04-13T07:13:55.569Z og:title: Scientists Have Identified the First Sexual Act on Earth og:description: And it looked a lot like square dancing og:url: https://time.com/3528344/scientists-fish-sex-square-dance/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt5200e69b15666b36/698761fd8e06015201457d45/screen-shot-2014-10-21-at-9-10-08-am.png?branch=production&width=1440&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Screen Shot 2014-10-21 at 9.10.08 AM og:type: article twitter:card: summary_large_image twitter:title: Scientists Have Identified the First Sexual Act on Earth twitter:description: And it looked a lot like square dancing twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt5200e69b15666b36/698761fd8e06015201457d45/screen-shot-2014-10-21-at-9-10-08-am.png?branch=production&width=1440&quality=75&auto=webp&crop=16:9 ---  # Scientists Trace Back the First Sexual Act Ever, to Weird Ancient Fish by [Laura Stampler](https://time.com/author/laura-stampler/) ## Laura Stampler Oct 21, 2014 2:18 PM UTC  YouTube by [Laura Stampler](https://time.com/author/laura-stampler/) ## Laura Stampler Oct 21, 2014 2:18 PM UTC Scientists have discovered the origins of sex, and like anyone’s first time it sounds pretty awkward. Now light some candles and let’s set the scene: The first act of copulation occurred in the nippy Scottish sea some 385 million years ago. The fornicators in question were a set of primitive jawed, bony fish aptly called _Microbrachius dicki_. The dirty details? Well, [according to Australian paleontologist John Long](http://blogs.flinders.edu.au/flinders-news/2014/10/20/flinders-scientist-discovers-origins-of-sex), “With their arms interlocked, these fish looked more like they are square dancing the do-se-do rather than mating.” Not only had scientists previously thought that the first sex act occurred on land at a later date, but Long [says](http://www.washingtonpost.com/news/morning-mix/wp/2014/10/20/scientists-discover-the-kinda-disgusting-origins-of-sex), “We didn’t expect these little suckers to have reproductive organs.” But the _M. Dicki_ were endowed, as is explained by Long and his colleagues in a paper that was published in [_Nature_](http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13825.html) Monday. Although their genitalia are not described in romantic terms. Long, a professor at Flinders University, explained to the [_BBC_](http://www.bbc.com/news/science-environment-29661446)that the fish’s arms linked them together, “so the male can get this large L-shaped sexual organ into position to dock with the female’s genital plates, which are very rough like cheese graters. They act like Velcro, locking the male organ into position to transfer sperm.” This is also the first species that displayed a different appearance between the male and female. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/3528344/scientists-fish-sex-square-dance/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/3528344/scientists-fish-sex-square-dance/"},"headline":"Scientists Trace Back the First Sexual Act Ever, to Weird Ancient Fish","datePublished":"2014-10-21T14:18:49.000Z","dateModified":"2026-04-13T07:13:55.569Z","description":"Ancient fish were the first to copulate. And according to a world renowned paleontologist, it looked a lot like square dancing","url":"https://time.com/3528344/scientists-fish-sex-square-dance/","keywords":["Newsfeed","animals","Sex","Studies","Evolution"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt5200e69b15666b36/698761fd8e06015201457d45/screen-shot-2014-10-21-at-9-10-08-am.png?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Laura Stampler","jobTitle":null,"url":"https://time.com/author/laura-stampler/"}],"articleSection":"","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt5200e69b15666b36/698761fd8e06015201457d45/screen-shot-2014-10-21-at-9-10-08-am.png?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Screen Shot 2014-10-21 at 9.10.08 AM","caption":"","creditText":"YouTube","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/tag/time-section-newsfeed/","name":"Newsfeed"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/3528344/scientists-fish-sex-square-dance/","name":"Scientists Trace Back the First Sexual Act Ever, to Weird Ancient Fish"}}]}] ```