Plesiosaurs Literally Flew Through Oceans

Why just swim when you can fly underwater? That’s essentially what an iconic Dino Era marine predator did.

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.

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"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.

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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.

click to play video

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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.

Most penguins are probably much slower than plesiosaurs were, based on the computer models. The majority of penguins only swim at about 7 miles per hour, yet the fastest penguin, the gentoo, merits a mention. It has been recorded swimming 22 mph. In contrast, the world's best human swimmers can only reach top speeds of over 5 mph.

A recreation of a swimming plesiosaur shed new light on how the creature swam.

We all enjoy a tall tale. Cultures with seafaring traditions are especially ripe in what seem like the tallest sea monster tales of all: hydra, kraken, sirens, scylla, leviathans, assorted serpents and mermaids. Usually the stories are never confirmed and deemed baseless. Then again, some of the tales are based on something. With our skeptical hats on, let's have a look at sea monsters both real and fanciful. We begin with a story that went viral just this week, about a supposed monster that revealed itself during a swim in the Thames River. A


bump in the water, filmed from overhead, started it all. But you'll have to judge for yourself: Real or fake? Watch the video and read

Ben Radford's take

on the tale.

'Thames Monster' Video: Hoax Or Mammal?

In keeping with our subject of monsters of the deep, we also learned this week that at least

some whales

really can, and will, use their heads for ramming -- just as the fictional Moby Dick did, in the Herman Melville classic of the same name. Did whales perfect the head-butt long before people started banging heads?

Real Moby Dick: Some Whales Ram With Their Heads

Sea monsters are truly global, of course. This one from Japan serves as the villain for the classic maiden in distress, who awaits rescue by her hero. The poor monsters are almost always cast as the bad guys. And so they usually end hacked to pieces; fish food. But is there any truth behind these sea serpent tales?

Ancient Sea Monsters Were Black

Maybe it's the oarfish. It looks too monstrous to be true. It can grow many meters long, has strikingly bright silver scales, scarlet fins and some ornate headgear that more than explains why some call it a roosterfish. If only it were a reptile, it'd be a true sea serpent. Alas. It is a fish. A very weird and beautiful fish, but still a fish.

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There are also other, newfound "sea serpents" our sea-going ancestors never imagined. This one was spotted by a satellite coiling off the south coast of Japan's Hokkaido island. What do we know about it? 1) It's arguably one of the largest organisms on Earth, 2) It swallows ships, engulfs islands and generally does what it wants, and 3) We're darned lucky it's made of plankton.

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Research into such massive blooms and the individual plankton cells that comprise them has revealed surprising cooperation among the microorganisms. They appear to operate like more than just floating individual cells. They live and die for the greater good, it seems. So they may be, in fact, a gigantic watery superorganism. Now that's a cool monster for you: You can swim in it and never know you've been in the belly of a beast.

VIDEO: Why Squid Are Terror Monsters Of The Sea

Mermaids and mermen have always been the stuff of fantasy. Where did the fantasies come from? There are some standard answers to this question, which have always seemed rather inadequate. For instance ... (next slide, if you please) ...

Mermaids Exist! And They Are Seismically Sensitive

The manatee has often been called the source of mermaid myths. It's a mammal, so it breathes air. But who would ever mistake a manatee for a sleek and beautiful mermaid? Could it be love-starved sailors with poor eyesight? There was no shortage of these fellows in the days before optometrists.

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Another possibility is that merfolk were inspired by fish with roughly human-looking faces, like this fellow. Some fish can look humanoid. That would be enough to get superstitious sailors started.

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How about giant, ship-destroying squid and octopi? These monsters were old hat even to the easily freaked-out. Most folks figured they were historical exaggerations. That's until some very large and unusual squids started washing up or being hauled in by marine biologists in recent years. Colossal squid are meters long, pretty amazing beasts. Still, they have never been known to lift ships out of the water. And since were on the topic of squids ...

Giant Squid Photos

Do you remember when this one hit the headlines? It's not so gigantic, at four meters long, but it was observed 3,380 meters down in the Pacific Ocean near Oahu. It's pretty big to have gone unseen before its May 2001 discovery. So what else is out there? It's pretty clear marine biologists have only just begun discovering what lives in the deep sea. The more time they spend searching, the more they will find. But none would dispute that the nastiest sea monster to ever rise out of the sea is ... (drum roll please) ...

You might have guessed it: Human garbage. Yep. It's the ugliest, most alien-looking, fatal and pervasive monster in the seas. Garbage patches have been getting a lot of attention lately. These are areas on the seas where currents and winds tend to concentrate floating garbage.

Life On The Ocean Floor Garbage Patch: Photos