Plesiosaurs Swam Like Penguins By Jasper Nikki De La Cruz | Dec 20, 2015 09:14 PM EST The plesiosaurs has something in common with the penguins. Both creatures share the same mechanical movements when it comes to swimming. The Plesiosaurs thrived in the seas when the Earth was still ruled by dinosaurs. These marine reptiles use their flippers like they are "flying" underwater. This movement is similar to penguins. The plesiosaurs had four large flippers. They also had long necks; hence, they were mostly associated with the Loch Ness monster. This kind of dinosaur lived from about 200 million to 66 million years ago. The plesiosaur fossils were first described in 1824. Even then, scientists had been debating on how these creatures swam. "Plesiosaur swimming has remained a mystery for almost 200 years because it is difficult to determine how an extinct animal with a unique body plan moved," Adam Smith, one of the Britain's Nottingham Natural History Museum paleontologists, said. Watch video Researchers used computer simulations based on the anatomy of the Meyerasaurus. They used such in order to find the most effective swimming strategy for its body design. The method that produced the fastest forward speed was the one where the two front flippers were flapping in an up and down direction. This makes it similar to an underwater flying motion to penguins and sea turtles. The rear flippers were believed to be used in steering and providing stability. "What was unexpected was that no matter what motion we simulated for the back flippers, they could not substantially contribute to the plesiosaur's forward motion," Greg Turk, Georgia Institute of Technology computer science professor, said. Another research had suggested though that plesiosaurs moved their limbs in a backward and forward motion, which can be easily equated to "rowing." Underwater "flying" is unusual for swimming animals like fish and whales. These animals use their tails in generating thrust. Plesiosaurs have it in a very different manner.