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7 Myths and Misconceptions About Crocodilians, Debunked

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There are a lot of myths out there about crocodilians, the order to which both alligators and crocodiles belong. Evon Hekkala, the principal investigator at Fordham University’s Hekkala Lab and a research associate at the American Museum of Natural History, spoke with mental_floss after the opening of AMNH’s latest exhibition, “Crocs: Ancient Predators in a Modern World,” to get to the truth.

1. MYTH: THEY CAN RUN AS FAST AS A RACEHORSE.

Winning Brew, the Guinness World Record holder for Fastest Racehorse, clocked in at nearly 44 mph during her record-breaking run. Crocs don’t get anywhere near that fast on land. “They top out at about 12 mph on land, and they can only do it for a really short period of time—for maybe 20 or 25 meters,” Hekkala says. “A really fast human race walker, goes about 11 or 12 miles on land. In other words, without even breaking into a run, most people could actually outrun a crocodile.”

In the water, though, it’s a different story: Crocs still aren’t as fast as racehorses, but they can reach speeds a little over 20 mph. “I wouldn’t want to try to outrun one in the water,” Hekkala says.

2. MISCONCEPTION: THEY’RE LIZARDS.

Though people often refer to crocodilians as lizards, lizards are an entirely separate order not related to crocodilians at all. According to Hekkala, “[Crocodilians] are the other lineage of living archosaurs,” a.k.a. “ruling reptiles,” which have two lineages: “There’s the lineage that includes dinosaurs and birds and then there’s the lineage that includes crocodiles, and they’re each other’s closest relatives,” she says. “They’re quite distant from lizards, even though they look sort of superficially similar.” And speaking of that …

3. MISCONCEPTION: CROCODILES AND ALLIGATORS ARE BASICALLY THE SAME.

Though crocodiles and alligators look very similar, their last common ancestor lived 65 million years ago. “That’s about as far back in time as when the primates diverged from things like bats,” Hekkala says. “They look really similar because it’s a really great body plan that works really well, and there’s no need to change that. So even though they look superficially like they’re the same thing, they’ve evolved on different pathways for a really long period of time.”

4. MYTH: THEY’RE DUMB.

“A lot of people think [crocodilians have] tiny lizard brains,” Hekkala says. “But actually there are people at the American Museum of Natural History who are studying the evolution of the brain in birds, dinosaurs, and crocodilians, and the brain is much more complex than we previously thought.”

Like birds, crocodilians have complex social systems (more on that in a minute), and they can even be trained. “There are people recently who have been training captive populations of crocodiles to come to a clicker so that they can get their veterinary treatment, and it’s working,” Hekkala says. Crocs can be trained the same way you train a dog or a cat: The croc comes to the clicker and gets a treat, reinforcing the desired behavior.

5. MISCONCEPTION: THEY EAT THEIR YOUNG.

OK, now on to that complex social behavior. “There was a myth, for a long time, that crocodilians were these terribly baby-eating predators,” Hekkala says. “A long time ago, people would observe the crocodiles and alligators digging up nests and having hatchlings in their mouths, and they would think that they were eating them.” In reality, the baby crocodilians were actually calling out to their parents for help out of the nest as they were hatching, and when moms were walking around with babies in their mouths, it was because they were taking their young to the water. “There’s parental care and communication,” Hekkala says. Male crocodilians will occasionally cannibalize young, but “typically, when you see a crocodile or an alligator with babies in its mouth, it’s helping, not hurting.”

The animals can delicately carry their young thanks to pressure sensitive pits in their skin. “Alligators only have them on part of their jaw, but crocodiles actually have the pits all over their skin, everywhere—all over their face, all over their bodies, and they’re unbelievably sensitive to pressure, and these were only recently discovered,” Hekkala says. “It’s an amazing new finding, and that’s probably one of the things that allows them to be so gentle with the hatchlings.”

6. MYTH: THEIR SKIN IS SUPER HARD.

If you looked at a crocodilian, or had a purse made of their skin, and thought their armored skin was super hard, you wouldn’t be alone. “Most people’s experience of any kind of crocodilian skin is a tanned leather purse or something like that,” Hekkala says. “Those things are made to be hard so they can be sturdy, but their skin is actually quite soft, and very sensitive.”

Rather than having scales like lizards, crocodilians have skin with bony plates underneath in certain areas. “This is going to sound weird,” Hekkala says, “but if you were holding a crocodile’s hand, it would feel strangely similar to a human hand. A little cooler unless they’d been hanging out in the sun, but yeah.”

7. MISCONCEPTION: THERE ARE TWO LIVING CROCODILIANS—ALLIGATORS AND CROCODILES.

Millions of years ago, crocodilians were a very diverse group, living in the sea and on land and ranging in size from small, cat-like creatures to creatures huge enough to dine on T. rex. These days, most people think that there are just two living crocodilians—alligators and crocodiles—but there are actually many more than that. “There are two species of alligator: the one we’re familiar with in North America, and the Chinese alligator, which is critically endangered,” Hekkala says. “When I first started my research into crocodiles, there were thought to be 11 species of true crocodiles in the genus Crocodylus, but we’re discovering more and more species.”

By analyzing the DNA of museum specimens, Hekkala discovered that the Nile crocodile was not one species of croc but actually two. And that was not an outlier: “Now we know that the dwarf crocodile that’s in the exhibit is three species, and we think that the African slender snouted crocodile is now two species,” she says. “So since 2009, just from molecular research, we’ve added—just in Africa—four new species of crocodile.”

The American Museum of Natural History’s “Crocs: Ancient Predators in a Modern World” runs until January 2, 2017.

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Big Questions
What's the Difference Between Gophers and Groundhogs?
Gopher or groundhog? (If you chose gopher, you're correct.)
Gopher or groundhog? (If you chose gopher, you're correct.)
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Gophers and groundhogs. Groundhogs and gophers. They're both deceptively cuddly woodland rodents that scurry through underground tunnels and chow down on plants. But whether you're a nature nerd, a Golden Gophers football fan, or planning a pre-spring trip to Punxsutawney, Pennsylvania, you might want to know the difference between groundhogs and gophers.

Despite their similar appearances and burrowing habits, groundhogs and gophers don't have a whole lot in common—they don't even belong to the same family. For example, gophers belong to the family Geomyidae, a group that includes pocket gophers (sometimes referred to as "true" gophers), kangaroo rats, and pocket mice.

Groundhogs, meanwhile, are members of the Sciuridae (meaning shadow-tail) family and belong to the genus Marmota. Marmots are diurnal ground squirrels, Daniel Blumstein, a UCLA biologist and marmot expert, tells Mental Floss. "There are 15 species of marmot, and groundhogs are one of them," he explains.

Science aside, there are plenty of other visible differences between the two animals. Gophers, for example, have hairless tails, protruding yellow or brownish teeth, and fur-lined cheek pockets for storing food—all traits that make them different from groundhogs. The feet of gophers are often pink, while groundhogs have brown or black feet. And while the tiny gopher tends to weigh around two or so pounds, groundhogs can grow to around 13 pounds.

While both types of rodent eat mostly vegetation, gophers prefer roots and tubers (much to the dismay of gardeners trying to plant new specimens), while groundhogs like vegetation and fruits. This means that the former animals rarely emerge from their burrows, while the latter are more commonly seen out and about.

Groundhogs "have burrows underground they use for safety, and they hibernate in their burrows," Blumstein says. "They're active during the day above ground, eating a variety of plants and running back to their burrows to safety. If it's too hot, they'll go back into their burrow. If the weather gets crappy, they'll go back into their burrow during the day as well."

But that doesn't necessarily mean that gophers are the more reclusive of the two, as groundhogs famously hibernate during the winter. Gophers, on the other hand, remain active—and wreck lawns—year-round.

"What's really interesting is if you go to a place where there's gophers, in the spring, what you'll see are what is called eskers," or winding mounds of soil, Blumstein says [PDF]. "Basically, they dig all winter long through the earth, but then they tunnel through snow, and they leave dirt in these snow tunnels."

If all this rodent talk has you now thinking about woodchucks and other woodland creatures, know that groundhogs have plenty of nicknames, including "whistle-pig" and "woodchuck," while the only nicknames for gophers appear to be bitter monikers coined by Wisconsin Badgers fans.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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Animals
Watch Christmas Island’s Annual Crab Migration on Google Street View
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Every year, the 45 million or so red crabs on the remote Australian territory of Christmas Island migrate en masse from their forest burrows down to the ocean to mate, and so the female crabs can release their eggs into the sea to hatch. The migration starts during the fall, and the number of crabs on the beach often peaks in December. This year, you don’t have to be on Christmas Island to witness the spectacular crustacean event, as New Atlas reports. You can see it on Google Street View.

Watching the sheer density of crabs scuttling across roads, boardwalks, and beaches is a rare visual treat. According to the Google blog, this year’s crabtacular finale is forecasted for December 16, and Parks Australia crab expert Alasdair Grigg will be there with the Street View Trekker to capture it. That is likely to be the day when crab populations on the beaches will be at their peak, giving you the best view of the action.

Crabs scuttle across the forest floor while a man with a Google Street View Trekker walks behind them.
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Google Street View is already a repository for a number of armchair travel experiences. You can digitally explore remote locations in Antarctica, recreations of ancient cities, and even the International Space Station. You can essentially see the whole world without ever logging off your computer.

Sadly, because Street View isn’t live, you won’t be able to see the migration as it happens. The image collection won’t be available until sometime in early 2018. But it’ll be worth the wait, we promise. For a sneak preview, watch Parks Australia’s video of the 2012 event here.

[h/t New Atlas]

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