When dinosaurs ruled the land, plesiosaurs ruled the oceans. Famous for their incredibly long necks – some of which were up to 7 metres long – plesiosaurs have remained an evolutionary mystery for hundreds of years. Pernille V. Troelsen, a PhD student at Liverpool John Moores University, UK is simulating plesiosaur locomotion with a 3D model to understand how they could swim with such long necks.