Plesiosaurs Literally Flew Through Oceans

Dinosaur Era marine reptiles known as plesiosaurs literally flew through the water, according to new research that found their swimming technique was very similar to that of birds in flight.

The discovery, reported in the journal PLOS Computational Biology, solves a longstanding plesiosaur puzzle over how these now-extinct animals used their unusual, four-flippered body to swim through the ocean.

“Plesiosaur swimming has remained a mystery for almost 200 years, so it was exciting to see the plesiosaur come alive on the computer screen,” co-author Adam Smith of the Nottingham Natural History Museum said in a press release.

The “computer screen” refers to computer simulations that he, lead author Shiqlu Liu of the Georgia Institute of Technology and their colleagues created.

Based on fossil finds, the scientists modeled plesiosaurs. They then simulated thousands of different swimming motions to see which ones would have been the most effective, given the plesiosaur’s unique body plan.

Surprisingly, flapping the rear flippers did not increase forward speed much.

“Our simulations show that the forelimbs provide the majority of thrust, and that the thrust from the hind limbs is weak,” explained the researchers. “The plesiosaur swims primarily with its forelimbs using an underwater flight stroke, essentially the same as turtles and penguins.”

Mosasaurs, another group of predatory marine reptiles that is now extinct, also had four flippers. They are featured in the below Discovery production from 2012, which took an educated guess, based on research at the time, on how they moved.

With the latest findings, expect future recreations of these iconic marine predators (which sometimes became prey themselves to sharks) to reflect the newly determined underwater flight move.

The new study also suggests how penguins managed to evolve from being flying birds to such good swimmers. Penguins used to have hollow bones and wings, but the bones became denser over time and the wings evolved into tapered, flattened flippers. They basically flap their flippers, however, just as the plesiosaurs did, to travel through water.

Read more at Discovery News