7 Myths and Misconceptions About Crocodilians, Debunked


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.


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.


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 …


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.”


“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.


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.”


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.”


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.

Why Tiny 'Hedgehog Highways' Are Popping Up Around London

Hedgehogs as pets have gained popularity in recent years, but in many parts of the world, they're still wild animals. That includes London, where close to a million of the creatures roam streets, parks, and gardens, seeking out wood and vegetation to take refuge in. Now, Atlas Obscura reports that animal activists are transforming the city into a more hospitable environment for hedgehogs.

Barnes Hedgehogs, a group founded by Michel Birkenwald in the London neighborhood of Barnes four years ago, is responsible for drilling tiny "hedgehog highways" through walls around London. The passages are just wide enough for the animals to climb through, making it easier for them to travel from one green space to the next.

London's wild hedgehog population has seen a sharp decline in recent decades. Though it's hard to pin down accurate numbers for the elusive animals, surveys have shown that the British population has dwindled by tens of millions since the 1950s. This is due to factors like human development and habitat destruction by farmers who aren't fond of the unattractive shrubs, hedges, and dead wood that hedgehogs use as their homes.

When such environments are left to grow, they can still be hard for hedgehogs to access. Carving hedgehog highways through the stone partitions and wooden fences bordering parks and gardens is one way Barnes Hedgehogs is making life in the big city a little easier for its most prickly residents.

[h/t Atlas Obscura]

Penn Vet Working Dog Center
Stones, Bones, and Wrecks
New Program Trains Dogs to Sniff Out Art Smugglers
Penn Vet Working Dog Center
Penn Vet Working Dog Center

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

A yellow Lab sniffs a metal cage designed to train dogs on scent detection.
Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

A dog looks out over the metal "pinhweel" training mechanism.
Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.


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