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Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,

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Speaker 1: Lauren Volga bomb here with a classic episode from our

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Speaker 1: erstwhile host, Christian Sagar. Lots of animals that roamed the

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Speaker 1: Earth during the time of the dinosaurs weren't quite like

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Speaker 1: anything we humans have ever seen, including many that aren't

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Speaker 1: classified as dinosaurs, like the plesiosaurs. Hey brain Stuff, it's

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Speaker 1: Christian Saga. From two hundred and twenty to sixty six

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Speaker 1: million years ago, a strange order of marine reptiles called

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Speaker 1: plesiosaurs roamed Earth's oceans. Though they were a diverse bunch

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Speaker 1: in many respects, every known species did share one major trait.

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Speaker 1: They all had four broad, paddle like flippers, and in

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Speaker 1: most cases, the hind pair almost looked like a duplicate

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Speaker 1: of the front set, both in size and shape. That

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Speaker 1: makes plesiosaurs, which were not dinosaurs but lived at the

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Speaker 1: same time, unique among ocean going vertebrates. That's because no

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Speaker 1: other marine reptile or mammal extinct or extent sports four

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Speaker 1: flippers of similar size. So how did this unique body

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Speaker 1: plan work? Researchers might have just found the answer. On August,

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Speaker 1: an international team of scientists published a new study on

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Speaker 1: plesiosaur locomotion headed by paleontologists Luke Musket. The group used

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Speaker 1: measurements from a pair of British species to construct two

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Speaker 1: replica flippers, one four limb and one hind limb with

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Speaker 1: three D printing technology. These were affixed to a custom

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Speaker 1: built robot which moved the replicas around in a tank

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Speaker 1: of water to see exactly how the paddles would churn

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Speaker 1: things up. Musket and company released colorful dyes into the

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Speaker 1: tank as well and tracked their motion through water. Afterwards,

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Speaker 1: the scientists put the robotic legs through numerous simulations designed

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Speaker 1: to test out different swimming styles. They found that the

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Speaker 1: most energy efficient stroke called for both flippers to work

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Speaker 1: in concert. When the front limb flapped in this test,

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Speaker 1: it created two vortices in the water. As the current

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Speaker 1: pushed these backward, the hind flipper weaved in between them.

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Speaker 1: By capitalizing on the wake generated by its frontal counterpart,

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Speaker 1: The rear limb made its own flapping motion si more powerful,

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Speaker 1: and this finding actually contradicts a study which argued that

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Speaker 1: plesiosaurs swam like sea turtles, using their four limbs to

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Speaker 1: push themselves forward while their rear paddles acted as rudders

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Speaker 1: using the robot Muskets team also tested this existing hypothesis.

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Speaker 1: They found that the rear paddles tended to produce drag

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Speaker 1: if kept in a stationary position, but by using all

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Speaker 1: four paddles to actively generate thrust, a plea asiosaur could

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Speaker 1: move more efficiently. However, the co authors acknowledge that, like

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Speaker 1: most aquatic animals, plesisaurs probably adjusted their swimming style as

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Speaker 1: the situation called for it. Furthermore, the study is complicated

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Speaker 1: by the fact that several Plesia saur species had four

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Speaker 1: limbs that were noticeably longer than their rear ones or

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Speaker 1: vice versa. Looks like follow up research will have to

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Speaker 1: take species specific data into account. Today's episode was written

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Speaker 1: by Mark Mancini and produced by Dylan Fagan and Tyler Clang.

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Speaker 1: For more on this and lots of other unusual topics,

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Speaker 1: visit how stuff works dot com. Brain Stuff is production

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Speaker 1: of iHeart Radio. For more podcasts my heart Radio, visit

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