Plesiosaurs maintained the same basic four-flipper body plan across their 135 million year history, yet there is no modern-day swimmer with a similar flipper arrangement. Numerous proposals have been made about the motions of their flippers during swimming. This computer-generated image shows the 3D model of Meyerasaurus victor that was used to study plesiosaur swimming. Thousands of different periodic motions of the flippers were tried using computer simulation. Numerical optimization determined that the fastest swimming motion uses the front flippers in an underwater flight stroke, and that the back flippers could not substantially contribute to forward motion. Turk et al.

Image Credit: Shiqiu Liu