Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, Lauren Volga bomb here with a classic episode from our erstwhile host, Christian Sagar. Lots of animals that roamed the Earth during the time of the dinosaurs weren't quite like anything we humans have ever seen, including many that aren't classified as dinosaurs, like the plesiosaurs. Hey brain Stuff, it's Christian Saga. From two hundred and twenty to sixty six million years ago, a strange order of marine reptiles called
plesiosaurs roamed Earth's oceans. Though they were a diverse bunch in many respects, every known species did share one major trait. They all had four broad, paddle like flippers, and in most cases, the hind pair almost looked like a duplicate of the front set, both in size and shape. That makes plesiosaurs, which were not dinosaurs but lived at the same time, unique among ocean going vertebrates. That's because no other marine reptile or mammal extinct or extent sports four
flippers of similar size. So how did this unique body plan work? Researchers might have just found the answer. On August, an international team of scientists published a new study on plesiosaur locomotion headed by paleontologists Luke Musket. The group used measurements from a pair of British species to construct two replica flippers, one four limb and one hind limb with
three D printing technology. These were affixed to a custom built robot which moved the replicas around in a tank of water to see exactly how the paddles would churn things up. Musket and company released colorful dyes into the tank as well and tracked their motion through water. Afterwards, the scientists put the robotic legs through numerous simulations designed to test out different swimming styles. They found that the most energy efficient stroke called for both flippers to work
in concert. When the front limb flapped in this test, it created two vortices in the water. As the current pushed these backward, the hind flipper weaved in between them.
By capitalizing on the wake generated by its frontal counterpart, The rear limb made its own flapping motion si more powerful, and this finding actually contradicts a study which argued that plesiosaurs swam like sea turtles, using their four limbs to push themselves forward while their rear paddles acted as rudders using the robot Muskets team also tested this existing hypothesis.
They found that the rear paddles tended to produce drag if kept in a stationary position, but by using all four paddles to actively generate thrust, a plea asiosaur could move more efficiently. However, the co authors acknowledge that, like most aquatic animals, plesisaurs probably adjusted their swimming style as the situation called for it. Furthermore, the study is complicated by the fact that several Plesia saur species had four limbs that were noticeably longer than their rear ones or
vice versa. Looks like follow up research will have to take species specific data into account. Today's episode was written by Mark Mancini and produced by Dylan Fagan and Tyler Clang. For more on this and lots of other unusual topics, visit how stuff works dot com. Brain Stuff is production of iHeart Radio. For more podcasts my heart Radio, visit the iHeart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.