Science Friday
Hosted by Flora Lichtman and Ira Flatow
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Fossils suggest there were ancient scorpions over 3 feet long. Terrifying? Perhaps, but there’s a lot to love about these arachnids.
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Hey, it's Flora, and you're listening to Science Friday. If you have arachnophobia, consider this your opportunity to try exposure therapy because scorpions ahead. A new study suggests that 415 million years ago, in modern day England and Wales, a scorpion the length of a golden retriever was scurrying around, complete with six-inch pincers. Some of these specimens were discovered long ago, and paleontologists had categorized them as sea-dwelling crustaceans. But a fresh look at these old fossils suggests they're not an ancient lobster at all. Dr. Richie Howard is the curator of fossil arthropods at the Natural History Museum
in London, England, and the lead author on this gigantoscorpion study. Richie, welcome to Science Friday.
Hey, great to be here. Thank you very much.
I've seen this, these specimens described as chonky. Does that sound right to you?
Yeah, I would say so. They are pretty big. They are an order of magnitude larger than any other fossil scorpion that we know of. But it's also worth considering that fossils are incomplete. It's sort of a dig saw puzzle of an animal. And so we have multiple parts of its body, but not the whole thing in one place. So it's difficult to say exactly how big it was. That's why it's roughly, we're saying roughly about a meter, roughly three feet long.
Wow, OK. You know, from the pieces you have, does it seem like it looked like just an inflated version of a modern scorpion? Or is the morphology different?
Yeah, it did look really different to a modern scorpion. So in an arachnid, the posterior part of the body is called the epistosoma. And the epistosoma is divided in scorpions specifically into the mesosoma, which is the fat bit, and the Metasoma, which is the tail, but the sting on the end. On the metasoma of this scorpion, we have what called lateral epimera extending out of the segments. So these are sort of like wing shaped bits. They're very reminiscent, I think, of a horseshoe crab or a trilobite.
Should I picture like those lobster bits on the tail?
Kind of, yeah, yeah. These are unique among scorpions. So that suggests to us that this was doing something different to other scorpions. I think the most likely explanation for that is that it was at least partially aquatic.
Were these scorpions, I mean, can we extrapolate what their role in the ecosystem? Were they like the grizzly bears of their time?
Yes, this is one of the weirdest elements of the whole study, really. So the early Devonian period when Prearchurs lived is a strikingly alien landscape. So I think people are vaguely aware that there were giant arthropods in Earth's deep paleontological past.
Like the two foot dragonfly and the eight foot long millipede, right?
Yeah, exactly, exactly. But they lived in the Carboniferous Period. This was 55 million years after when Prearchurs lived. That's a world where there are jungles because trees have evolved. It's a world where there is a much more complicated, complex landscape in terms of ecology. In the early Devonian, life has only really just started spreading onto the land. There's just some gigantic scorpion running around as well. It's kind of crazy. It's walking around in between all these sort of primitive moss-like plants and these sort of tall, weird, fungousy things called prototaxites. Basically look a bit like standing stones. Really, really, really weird landscape this animal lived in.
And of course, that answers the question, how on earth did it sustain itself? Unless there's loads of other large animals on the land at this point that we just don't have the fossils of, which I think is probably unlikely because how have we just missed? We've missed all of them. I think what's more likely is that it was an amphibious animal. There's much larger prey for it in the water, things like armored fish. They've been found at some of these sites as well.
So your work revolves around, you know, to me, I'll just show my cards, this terrifying ancient, ancient arthropods.
What are your feelings on modern ones?
Well, I never would have got interested in fossil ones if I hadn't been interested in modern ones as well, because the modern ones are all around us. I love the modern ones. I can't go outside without taking photos. I always want to know what arthropods are, because they're literally like little Pokémon that are everywhere. So, yeah, I think if you're not interested in arthropods, you're not interested in life.
"Don't sleep on the arthropods," is what I'm hearing. Richie, thank you for being here.
No worries. Thank you for having me.
Dr. Richie Howard, invertebrate paleontologist and curator of fossil arthropods at the Natural History Museum in London, England. After the break, can you learn to love the scorpion? We're gonna try. Stay with us.
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If you are icked out by a scorpion the length of a Labrador, you're likely not alone. A study in the musings section of American entomologists found that people feared scorpions above even spiders, and they're like a phobia chart topper in America. But my next guest says we have it all wrong. Here to help us stop worrying and to help learn to love the scorpion is arachnologist Dr. Lauren Esposito, a scorpion researcher and director of the nonprofit Islands and Seas. Lauren, welcome back to Science Friday.
Happy to be here.
Okay, give me three words to describe your feelings on scorpions.
All right, my three words are caring, ancient, and I would say intriguing is the biggest thing that has kept me interested in scorpions for the last 20 years of my life.
Intriguing. Oh, my gosh. I'm not hearing repulsion.
Absolutely not. Absolutely not.
Okay, well, I'm gonna stand in for the vast majority of people who feel the opposite, who would rather never encounter a scorpion. And your mission today, if you choose to accept it, is to change our minds with facts. And I'm also gonna give you categories, kind of like Jeopardy, and I want you to hit me with a story or some facts from the category that you think will make
Me and mostly our listeners, see scorpions the way you do. Do you accept?
I accept the mission.
Okay, all right. First category is food and drink.
Food and drink. Well, food and drink is a big one because scorpions have the lowest metabolic rate of any recorded land animal, which is like move over weight loss drugs because it should be the scorpions that we're studying.
Wait, heal monsters, I feel like are the poster child for low metabolism.
I would say that that's true when we think about things that have a backbone like vertebrates. Heal monsters are great for low metabolism, but scorpions, they only need to eat really like once a year or maybe even less frequently than that. They don't typically need to drink water. They get all the water that they need from their prey items. And they have these like really cool adaptations to be able to restrict the amount of water that they lose. So they have book lungs. The way that they breathe is through these like internalized gill structures. So they don't like actively respire like breathing in and out, which definitely like helps reduce their metabolism.
Oh, my gosh. So book lungs, like the pages of a book, like I should be imagining the leaves of a book.
You should, like, if you think about like a fish gill, like if you've ever seen a fish like opening their gill slits in and out, and there's all these kind of like pages inside there of gills. Imagine if they just took all those gills and they squished them down and they stuck them inside a pocket in their body. So a lot of arachnids have book lungs and it's really a leftover from their ancestors that lived in the ocean. So before they moved on land, these were gills that were functioning in the ocean, just like fish gills.
Which we talked about in this last segment with this giant scorpion. Okay, I'm, I feel like my wonder meter's going up, but I'm still not, I'm not getting caring, uh, really.
We'll get there, we'll get there.
Okay. Our next category is anatomy.
Anatomy. Anatomy is a good one. One of my favorite things about scorpions, and I like to say that we're in the midst of a scorpion renaissance period, where we are discovering more information about scorpions than we've known cumulatively across all of history, like every single year.
Really?
Yeah, really.
Is it because people are just like jumping on the scorpion bandwagon?
I mean, I think that you'll be jumping on the scorpion bandwagon at the end of this conversation. But yes, that's part of it. Part of it is that there are simply more researchers studying scorpions than there's ever been. But I think the other part of it really has to do with a recent revelation that does have to do with anatomy. Scorpions have an exoskeleton, so their skeleton is on the outside of their body. But what's really cool about scorpions is that they have this pigment embedded in their exoskeleton that fluoresces under ultraviolet light. And so if you take like a black light, like a party light, normally you'd shine it on your shoelaces and you'd see they're like really bright and purple. But if you shine them on a scorpion, they glow this bright green color.
And what that's allowed us to do is to go out at night when they're active and look for them with UV light. It's like a secret weapon for detecting scorpions. And it's allowed us to discover way more species than we ever knew about. So like 100 years ago, we knew about something like 200 scorpions on Earth. And now we know about over 2,500.
What about their venom?
Okay, I mean, let's get to the brass tacks, which is scorpion venom, right? That's the thing that we're scared of. We're scared of scorpions stinging us because that's like the legends that we hear. Like you're gonna die instantly if a scorpion stings you. And I'm not gonna say that that's not true entirely, like universally, right? But that's untrue. Because there are places in the world where there are genuinely dangerous scorpions. But often the thing that makes them more dangerous is people's access to medical care. So nowadays, we have really effective antivenins that can counteract the effects of scorpion venom very well. And so if you can reach a hospital and get antivenom, you'll be able to survive a scorpion sting.
So the vast majority of scorpions pose no danger whatsoever to humans. Of the 2,500 scorpions on Earth, there's only about 50 or less that are dangerous to humans. Like 99% of scorpions don't pose any harm to humans.
But.
That is, that's helpful. Go ahead, go on.
The one percent are really interesting, not because they could kill you, um, which it's not actually the scorpion venom itself that can kill you. It's the effects of your body responding to this like trick that the venom plays on your brain. And so venom is a cocktail and one of the things in this cocktail is a neurotransmitter, um, inhibitor. And so what it does is it goes in and it interferes with the way that your cells signal each other, your nerve cells. And so it tells your brain that your hand is like experiencing some severe trauma, when all that's actually happened is you got a prick in your finger, like nothing else is going on other than the scorpion venom tricking your brain to think that you're like being smashed with a sledgehammer.
And what happens is that your brain turns on this immune response that raises your blood pressure and that really rapid increase in blood pressure can have downstream consequences like a heart attack. And the heart attack is ultimately what kills you. So it's not technically the scorpion, it's you.
It's me killing me, as always. Okay, let's get to my favorite category, mating and dating.
Scorpion dating is like pretty serious business. So here's how it works. Scorpions are out at night, checking, surveying the scene, seeing who's around. A male finds a female. He approaches her and as he approaches her, he starts kind of doing this like shuddering movement. That's like, almost like, hey, check me out, look at me. And
Like flashing his, his little, his pincers or his tail?
No, like shaking his entire body, like his whole body's shaking. Yeah.
Cool.
And as, if she doesn't react aggressively or run away, he keeps making slow movements towards her. And eventually he reaches out and grabs her hands with his hands and begins hands, like their claws are grabbing each other. So they're facing each other, they're holding hands and they start to dance. And we call this like in a scientific term, we call it a pas de deux, like a couples dance, a ballroom dance. And while all arachnids do some kind of mating ritual, like all of them kind of dance for each other or do some kind of thing that's interactive, scorpions are like the ballroom dancers of arachnids. So when I say it's like dating, it's really like kind of a courtship that is picky.
And they continue this dance for a while and eventually if the male does like a good enough dance, then he'll finally deposit sperm onto the ground. They deposited on this kind of jelly stalk that they comes out of their body and at the top of the stalk, they put a little package of sperm and he'll guide the female towards it because they're still holding hands. Oh, I forgot to say that they sometimes they kiss each other and they do occasionally sting each other in what we call sexual sting.
On the mouth?
Yes.
Like what?
Like they're facing each other and they'll put their squish their little scorpion mouths together and they'll like kiss each other with their mouth.
I feel like you're making this up Lauren and we'd never know because no one studies scorpions, but.
There's like 25 of us, come on.
Uh, and then sometimes there's a sting, which is like, you know, the sort of kinky side of dating, but eventually if she's pleased with all of this, then she'll pick up the sperm package that he's left for her and she'll store his sperm until she feels like the conditions are good for having babies and which point she'll inseminate herself.
Wow. So she has control over when she's getting pregnant?
She has control over when she's getting pregnant. So she like kind of evaluates the environment and if the conditions are good, if it's like a good rainy year with lots of prey, then she'll allow for internal fertilization using the sperm and the craziest thing is.
Where does she keep the sperm? Like in a purse? What? I don't understand.
It's like in a little scorpion purse inside her body, like genuinely. There's like a little pocket and she stores the sperm inside the pocket.
Let me just tuck this away for later. I gotta live my life. I gotta live my full life right now.
Exactly. She's living her best life until she gets pregnant. So scorpions, unlike all other arachnids and basically all insects for the most part, uh, they get pregnant. So they inseminate themselves and then that sperm, you know, combines with all the eggs that she has in her body and those eggs start to grow into embryos inside her body, just like a mammal gets pregnant and they don't come out until they're fully formed little scorpion legs.
Wait, live birth? Is that what you're telling me? That's unusual, right?
It's pretty unusual and they even like, it's so crazy because they come out in like a little amniotic sac, just like a vertebrate does. And then the sac bursts as she's giving birth and then they crawl up onto her back and she takes care of them after that.
How many in a litter?
Well, it depends. So like scorpions vary a lot in size and some smaller species maybe only have two scorpionlings. That's a technical term, scorpionlings.
That's, that's the first cute thing I've heard.
It is. It's cute. And then like in other species, the, the highest number recorded is like 156.
Oh.
That's a lot of babies.
And then she takes care of them.
Then she takes care of them. She keeps them on her back for the first, well, instar is a technical term, but it means like the first time they molt their exoskeleton and grow a new one. And at that point, they'll kind of start to wander away from her. Sometimes they'll stay a little longer. Sometimes they'll leave immediately, but um, that's sort of the end of the parent-child relationship.
Oh my God. What's your favorite scorpion fact?
My favorite scorpion fact is that we are still describing new species every single year from the United States.
Wow.
Which I think for me, that's like an important fact because as a kid, I always grew up thinking that we've discovered everything there is to discover. And if we find something that's like from some remote jungle out there in the world somewhere that nobody's ever been in before. But the reality is like, we're finding things from the Central Valley of California, which is one of the most high intensity agricultural areas in the world. So I think the really cool thing about scorpions is there's so much left to learn and we need so many more scorpion biologists to do it.
That's right. Get over your ick, young budding scientists. There's a whole scorpion world out there. Lauren, I think you've convinced me. I think you've, you've done it. They're amazing and there's so much more to learn.
Yay for scorpions.
Thank you. Thank you for coming on and doing this.
Thank you. It was a pleasure.
What about you listeners? Did we convince you scorpion skeptics to become scorpion stans? Give us a call, 8774 sci fry is our number. And if you have any other scorpion questions, we know who to call. This episode was produced by Shoshana Buxbaum. I'm Flora Lichtman. We'll catch you next time.
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