NPR

Utah's Fossil Finds Describe an Ancient World

Once upon a time, giants roamed the planet — many of them in what is now Utah. A panel of paleontology experts describes some of the state's ancient treasures, from massive long-necked sauropods to the Utahraptor, a predator that would put those in Jurassic Park to shame.

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Transcript

IRA FLATOW, HOST:

This is SCIENCE FRIDAY, I'm Ira Flatow. If you're into old stuff, Utah is a great place to be, and I don't mean "Antiques Roadshow" vintage kind of stuff. I mean really old stuff. Think "Jurassic Park" and older. The climate and geology of Utah make this state a fantastic finding-fossils place, for some of the old favorite dinosaurs you recall from your childhood picture books, you know, to plenty of new species found in Utah for the first time.

And remember, there's more out there than just dinosaurs. Fossil remains of other plants and animals are helping paint a better picture of what life was like on our planet millions of years ago. We're coming to you from Salt Lake City today as the guests of KUER, broadcasting from the Grand Theater at Salt Lake Community College, and we're here to talk paleontology.

And if you're here in the audience, please feel free to step up to the microphones. We've got one here, one there. We have one up in the balcony. Good to see the folks in the balcony up there, yeah.

(APPLAUSE)

FLATOW: If you want more information, you can always go to our website at sciencefriday.com. Let me introduce my guests, right to left, on your radio. Brooks Britt is an associate professor in the Department of Geological Sciences at Brigham Young University, just down the road a piece in Provo. Thanks for being with us today.

BROOKS BRITT: Thank you.

FLATOW: Brian Switek is a science writer. His new book, "My Beloved Brontosaurus: On the Road with Old Bones, New Science, and Our Favorite Dinosaurs," just out. Welcome to SCIENCE FRIDAY.

BRIAN SWITEK: I'm glad to be here.

FLATOW: Randall Irmis is the curator of paleontology at the Utah Natural History Museum. We had a great tour of that museum, and I tell you, go over there and take a look if you haven't been there. It's new and it's wonderful. He's also an assistant professor in the Department of Geology and Geophysics at the University of Utah here in Salt Lake. Welcome to SCIENCE FRIDAY.

RANDALL IRMIS: Thanks for having me.

FLATOW: Let me ask you first, you write in your book, Brian, that I came to Utah just for the dinosaurs.

Is that really why you came to Utah?

SWITEK: It's absolutely true.

FLATOW: Tell us what you mean, why you did that.

SWITEK: Well, the year before I moved here, I moved here in May of 2011, there are eight new species of dinosaurs just named from Utah alone. And there are more sort of in progress (unintelligible) ones out in the field that we haven't found yet. Really it's a dinosaur gold mine.

FLATOW: Really? Eight new ones?

SWITEK: Yes, just in one year alone.

FLATOW: Randall, tell us about what those new ones are.

IRMIS: There are a host of different ones. We have one sitting between us here, looming large, Utahceratops, with eponymous...

FLATOW: That's this one to my left, right here?

IRMIS: Yeah, right here. It's a new horned dinosaur from 75 million years ago in southern Utah.

FLATOW: Wow, and it's found in no other place?

IRMIS: No other place, and the only fossils are right here in Salt Lake City.

FLATOW: Is it - you know, it's got one horn on it, is that correct? Is it, like, related to triceratops, the one we've seen?

IRMIS: Yeah, it's a relative of triceratops and other horned dinosaurs. It's got a small horn over its nose and two horns over its eyes. And then it's got a big frill with various spikes and knobs coming off of it.

FLATOW: And we have another skull over here to my right. Which one is that one?

IRMIS: That's Allosaurus, Utah's state fossil. And over...

FLATOW: Did you all know this was the state fossil?

(LAUGHTER)

FLATOW: That's the state fossil.

IRMIS: The state fossil.

FLATOW: I don't think many states have a state fossil. They have a bird, a plant...

IRMIS: More than you'd suspect.

BRITT: Well, and the state bird's kind of the state dinosaur as well.

FLATOW: That's right, a bird is a dinosaur, so it's sort of two for one in the state. Now, what makes Utah so great for dinosaurs? Why so many dinosaurs and new dinosaurs? Anybody? I'll throw that open.

BRITT: It's our geology. It's the same reason we have five national parks, have national monuments. We're part of the Colorado Plateau, tremendous uplift, this upheaval, with any erosion exposing things that were buried kilometers below the surface, are exposed at the surface now. And unlike places like New Jersey or New York, which are covered with verdant landscapes of trees and grasses, Utah's pretty barren.

And so as you walk along, you can see the bones coming out of the ground.

FLATOW: Now, I asked somebody last night about this. I said: Can you actually go out in your backyard or on a roadside and kick up a dinosaur fossil? They say yeah. Have you all done that? Has anybody you discovered fossils?

(LAUGHTER)

FLATOW: You have? You can do that here?

SWITEK: Just have to know where to look.

FLATOW: Where is the best place to look? Where is the best place in the state to look?

BRITT: It's wherever the right age strata are exposed. Randy works in right now a lot of Triassic rocks. I'm working in early Cretaceous rocks. You get out the geologic map, you learn where the exposures are, and you load up your rigs, and off you go.

FLATOW: Wow.

IRMIS: And if you want to find fossils from 500 million years ago to the present, you can pretty much find a rock layer in Utah that has them.

FLATOW: What is different than what we know about dinosaurs? I mentioned we all, you know, we all grew up with dinosaurs. Brian, you talk about specifically the old brontosaurus, the poor brontosaurus, what it's gone through over the last three decades. What happened to it?

SWITEK: Well, it's a ghost. It's been dead for over a century, really, scientifically. You know, it was - turned out to be a synonym of another one of these long-necked heavy-bodied dinosaurs called Apatosaurus. That was figured out in 1903. But for whatever reason, it kind of stayed on the books. It stayed in museum exhibits, and it became the epitome of dinosaur-ness.

It was my entre to dinosaurs as a kid, and it was just at that time that they finally found the head, and they fixed the head problem. They used that to sort of spur this new image of a more active animal, more dynamic animal. But you know, we can't let it go. It's still this kind of ghost of a dinosaur that hangs around museum halls.

FLATOW: Yeah, I remember, and you write about it in your book, when they replaced the head, the famous brontosaurus at the American Museum of Natural History. You grew up there in that museum, right?

SWITEK: Well not in the museum...

(LAUGHTER)

SWITEK: I'm not ready to be committed to collections just yet.

FLATOW: You will be more valuable when you are.

SWITEK: Absolutely.

(LAUGHTER)

IRMIS: We can find a place for you, Brian.

FLATOW: Oh thank you, Randy, I look forward to it.

But that was like a seminal event for everybody growing up, so they're taking the old head off and putting - does that mean there was no such thing as a brontosaurus, it was always misnamed and miscalculated?

SWITEK: Well, the bones are real, the animal is real. If you go to the Yale Peabody Museum in New Haven, Connecticut, you can see the actual bones that Othniel Charles Marsh used to name brontosaurus. But the image of what a brontosaurus was, this slow, stupid, plodding animal that sort of just bathed in swamps all day and didn't do anything except eat and make little dinosaurs, that image is, you know, basically it's gone entirely now.

But to me it's an excellent baseline to gauge how our knowledge of dinosaurs has changed since brontosaurus was named.

FLATOW: If you have any questions in the audience, you'd like to step up to the microphone, the mics are out there. And you know, don't be the last one up there because you will never get your question in if you're the last one. I encourage you to do that.

Let's talk, Randy, a little bit - why are, what are some of the big misconceptions you see people have about paleontology? What do they think it is, and what is it really?

IRMIS: That we dig up humans, that's a big one.

FLATOW: They think you dig up humans?

IRMIS: Oh yeah, and human, you know, pots and stuff like that.

FLATOW: Do people - I remember reading a survey that 41 percent of Americans think that the Flintstones were real.

(LAUGHTER)

FLATOW: Maybe not that cartoon character but that people did live at the same time dinosaurs did, 41 percent.

IRMIS: Yeah, yeah, it's not uncommon. But, you know, it's because we have - we're talking about such a vast amount of time that it's hard to conceive, I think. And so a few thousand years ago is just as hard to conceive as 100 million years ago.

FLATOW: But they were separated by hundreds of millions of years.

IRMIS: Sixty-five or a little bit less.

FLATOW: That was the extinction of the last dinosaur, was about 65, when that big asteroid came in and...

IRMIS: Yeah, the coup de grace, so to speak.

FLATOW: The coup de grace. They were on their way out.

IRMIS: Well, that's under debate, but a lot of people think there were other things going on like big volcanic eruptions that were having an effect before the asteroid hit.

BRITT: And of course as you mentioned on some of the other shows, their descendants are still here among us, the birds, the most (unintelligible) group of vertebrates on land today, so...

FLATOW: Before I go to the question in the audience, Brian, let me ask you this question, sort of ask it delicately, about T-rex and marital relations, I'll put it that way.

(LAUGHTER)

FLATOW: People are trying to figure out why T. rex had such short little bony forearms, right? What would you do with that? But they came up with some interesting ideas.

SWITEK: Well yeah, in the original papers, Henry Fairfield Osborn, who named Tyrannosaurus rex, you know, he couldn't figure out, you know, why this massive sort of deep-skulled(ph), knife-toothed dinosaur would have such puny-looking arms. So he figured that maybe, you know, during mating the male sort of stroked or cuddled the female with these little arms.

But I'll tell you, you really shouldn't laugh at Tyrannosaurus rex. You couldn't beat an arm-wrestling contest with this dinosaur if you tried. Each arm could curl about 400 pounds apiece. If there's any dinosaur that deserves ridicule for this, there's one from South America called Carnotaurus that had arms that might have not even stuck outside of its body cavity.

You can pinwheel them around, but that's about it. So even Tyrannosaurus rex would laugh at this other dinosaur.

(LAUGHTER)

FLATOW: All right, all right. Well, I can't follow that up. So let's go the audience.

(LAUGHTER)

FLATOW: Let's go over to this gentleman right here. Yes, sir, first question before the break.

UNIDENTIFIED MAN: Thank you. Are there any ground-penetrating radars or anything that tell you how to find these things, or do you just wander around in the desert and stumble across them?

FLATOW: They'll never admit they wander around.

(LAUGHTER)

BRITT: It only works in movies, to be honest. You can find mammoths or mastodons. We have some difference in the density between the bones and the substrate. But with dinosaurs, it's never worked. So it's disappointing, I know, but it makes for spectacular footage, but it doesn't work because the bones and the rock typically are the same density.

So we're - here's the trick. We're always digging blind. You might see something on the surface, but you have you no idea what you're going to find below the surface.

FLATOW: What is it about the history of this area that makes a great place for where the dinosaurs were living?

BRITT: Well, dinosaurs lived on land. They didn't live in the ocean. They - except for birds, they didn't live in the air. And so you want to find sediment rocks that are composed of sediments that were deposited on land, so rivers, streams, lakes. And we had a lot of that through our geologic history during the age of dinosaurs.

FLATOW: And there was a giant inland sea, right, that stretched from where to where?

BRITT: From the Arctic all the way to the Gulf of Mexico, called the Western Interior Seaway, from about 90 million to 70 million years ago.

IRMIS: Yeah, so this used to be shorefront property during the Cretaceous.

BRITT: Property values were sky high.

(LAUGHTER)

BRITT: The mosquitoes would have been pretty bad.

FLATOW: Do we have time? I think it's time for a question. We have quick question, quick question here from the audience right before the break.

UNIDENTIFIED WOMAN: Triceratops is my favorite dinosaur, and I've been reading how there's now some dispute about maybe some of them are actually immature versions of another one. And I was wondering: How much dispute is there over classification?

IRMIS: There's quite a bit. I mean I'll tell you this right now: Triceratops is safe, you don't have to worry, you can sleep soundly tonight. Triceratops is not going anywhere. It's two other dinosaurs, called Torosaurus and Notoceratops, that are found in the same deposits, that seem like they're more mature versions of the same animal.

So do we have one dinosaur, or do we have three? And this is something that's very common in paleontology, and we're just working off anatomy most of the time. And you might find an infant, and you might find an adult, and name them two different species. But when you find those intermediate growth stages, it all comes together. So paleontology is constantly reshuffling the number of dinosaur species that we think we've got.

FLATOW: All right, thanks for that, great question. We're going to come back and take a lot of questions. I see people are at all the microphones. We'll come back with Randy Irmis and Brian Switek and also Brooks Britt. And stay with us, we'll be right back after this break.

(SOUNDBITE OF MUSIC)

FLATOW: This is SCIENCE FRIDAY. I'm Ira Flatow. We're in Salt Lake City talking about Utah paleontology, coming to you from the beautiful Grand Theater on the campus of Salt Lake Community College. My guests are Randall Irmis, Brooks Britt and Brian Switek, and we'll go right to the audience. Let's - yes, step up to the mic there.

UNIDENTIFIED MAN: Can I have two questions?

(LAUGHTER)

FLATOW: Can he have two questions? OK, let's - democratic about this. Go ahead, yeah, sure.

UNIDENTIFIED MAN: The first one is: So when I go to Moab, why do I never see bones, but I always see footprints?

FLATOW: When you go to Moab, you only see footprints, not bones?

IRMIS: They're - yeah, it's famous for both bones and footprints, actually. There are a number of dinosaur quarries. We have a crew down there excavating north of Moab right now. So you just don't - bones erode so rapidly, you rarely - you don't see them on the surface very often. But those footprints, at the right horizons, you'll find those quite a number of places down there, in Triassic, Jurassic and even in Cretaceous strata in that area.

FLATOW: And you had a second one, a bonus question?

UNIDENTIFIED MAN: How old are Allosauruses?

IRMIS: A hundred and fifty million years old, give or take a few.

(LAUGHTER)

FLATOW: You know what an Allosaurus is?

UNIDENTIFIED MAN: Yeah.

FLATOW: What is it?

UNIDENTIFIED MAN: They're...

FLATOW: Get up to the mic, please.

UNIDENTIFIED MAN: They're like raptors that stand for(ph) Utah?

FLATOW: Randy?

IRMIS: Yeah, they're large carnivorous dinosaurs like the skull that we have sitting in front of us here. Some of them got up to almost Tyrannosaurus rex size, not quite. And I could answer your question a different way. We know that they got to about 20 years old before they died.

FLATOW: That's how long they lived?

IRMIS: That's how long they lived, yeah.

FLATOW: Good questions. Thank you. Let's go way up into the balcony up there, up top, yes.

UNIDENTIFIED MAN: Hi, Ira, it's great to be here. It's awesome seeing you.

My question is: Over the 75 million to 150 million years ago, what happened geologically to make Utah a good place for dinosaurs? Was it - did our climate change, or where was Utah in the whole Pangaea thing? Where do we fit into this?

FLATOW: Yeah, anybody want to - Brian, Randy?

IRMIS: Yeah, Utah was in North America, of course, still at that time, and the continents were already splitting apart 150 million years ago and moving - starting to move northward a little bit. But there were no icecaps at either poles, and it was a hothouse world, as we call it. So it was pretty nice climate. It would have been warm, very warm during the summer.

And because the mountains had just started building in sort of Nevada and western Utah, that caused that part of the land to go up and then the land in eastern Utah and Colorado to go down. And that's why we got - part of the reason why got the seaway there.

FLATOW: So you wouldn't see the mountains we see now, back then?

IRMIS: But there would've been smaller mountains towards the west.

BRITT: And one of the other factors that made Utah great for dinosaurs is because there's this sort of barrier that hasn't been found yet that isolated dinosaurs north and south about 75 million years ago. I mean Utahceratops on the stage here is a great example of that, of unique dinosaurs that seemed to only exist in southern Utah or in the southern sort of range.

So it's almost like islands on continents. So you have the shoreline bayou-like environment, where you're having dinosaurs evolve in Utah that aren't seen anywhere else.

FLATOW: Very interesting.

IRMIS: One more factor was it's a basin. We don't have dinosaurs - we don't have any record of dinosaurs that lived in mountains because the paleo (unintelligible) eroded away. But you have records of dinosaurs that lived in areas that were actively being down-warped and filled with sediments, what we call a basin.

So the mountains that were off to the west of us here now provide sediment to fill in this basin, and the volcanoes off in that region as well, farther to the west and up to the north, settled in. The ash settled into these areas and preserved. So you need to have a basin that's - where the crust is down-warping.

FLATOW: That's our hashtag for today, down-warp. We're going to hashtag that one so everybody - yes?

UNIDENTIFIED MAN: So as a kid my favorite dinosaur was the Velociraptor, and then recently I found out that basically everything I know about that dinosaur is a lie.

(LAUGHTER)

UNIDENTIFIED MAN: So I was wondering what the differences are between my conception and, you know, with help of Steven Spielberg's Velociraptor, and the actual creature.

BRITT: Yeah, that's one thing: Velociraptor in "Jurassic Park" wasn't really Velociraptor. It was actually Dinodocus, this other sort of larger predatory, sickle-clawed dinosaur. The name got changed because Michael Crichton wrote a book that lumped the dinosaurs together in a weird way. And that's - you know, really, if you're going to make a Hollywood movie, you know, saying like you bred raptors, that's a lot more sort of dramatic than going you bred (unintelligible). I guess that's sort of a little more uncomfortable.

(LAUGHTER)

BRITT: But, you know, feathers is the main thing. I mean, Velociraptor and all these dinosaurs in this (unintelligible) group were very feathery, they were very avian. So they weren't sort of the scabrous, scaly, monstrous animals that you saw in "Jurassic Park." And the main thing, if you ever do an impression of a Velociraptor, you know, people mostly put their wrists down, their palms facing down, right?

But dinosaurs weren't slappers; they were clappers. So hands together. So if you take anything away from this today, just remember, dinosaurs are clappers and not slappers.

(LAUGHTER)

FLATOW: I'm feeling smarter already. How about the skin, Randy? At the museum, you were showing me some actual dinosaur skin, fossilized skin. It was kind of interesting.

IRMIS: The preservation in southern Utah we're working in Grand Staircase-Escalante National Monument, these are rocks that are about 75 million years old, it's truly amazing. We find duckbilled dinosaur skeletons, and they're one of the most common dinosaurs, but usually dinosaur skin impressions are incredibly rare.

In this case, about 60 percent of the skeletons we find have skin impressions of some sort, and some of them are covering entire portions of the tail or the body. And I've got actually a lower jaw of a duckbilled dinosaur right here in front of me. And Ira, you might be able to see these white marks here.

FLATOW: Yeah, yeah.

IRMIS: Those are where a giant crocodile bit the head of this duckbilled dinosaur 75 million years ago, and...

FLATOW: It must have hurt.

IRMIS: I think so, yeah.

(LAUGHTER)

FLATOW: Yeah, and so wow. And so that's how you - you find them together, and that's how you know who feeds on what...

IRMIS: In this case we didn't find the crocodile, but it turns out that carnivorous dinosaurs make slightly different bite marks than crocodiles, versus mammals. And so we can tell based on the shape of the marks who made them.

FLATOW: That's terrific. Let's go down here. Yes, sir.

UNIDENTIFIED MAN: What is the average life span of a Utahraptor?

BRITT: I happen to have a femur of Utahraptor here in front of me. It's a little over a half a meter long. And by cutting through these bones and looking at the different layers, they're called lines of arrested growth, which is this fancy way of saying growth lines, just like in tree rings, we can tell they - the oldest one we have, and we have nine individuals of these, reached the age of 17 years. That's a great question. I like that.

FLATOW: You know, why don't you hold the bones up? We have another big bone that's in the front here. What bone is that one?

IRMIS: That's a cast of the femur of Apatosaurus, the so-called brontosaur that he was talking about. And so that's about as all as I am, it's just about six feet tall.

FLATOW: You know, when I talked to dinosaur experts years ago about dinosaurs being birds, they said go to the museum, and bring a chicken wing with you, or bring a chicken leg, and hold it up to the bone that you see. They'll look identical, almost identical kind of bone and the shape that - that's one of the reasons why we think they're related.

IRMIS: Absolutely. When I was working on Tyrannosaurus a number of years ago, I'd have a little pigeon skeleton mount on the desk, and then I'd have the Tyrannosaur bones scattered around me. And if there was an articulation you couldn't understand, you could go look at the bird and largely figure that out.

BRITT: You won't see it at every museum, but if you go to up-to-date museums, and you know where to look, you can actually see dinosaur wishbones as well. If you look at the chest of Tyrannosaurus rex, if it's really up to date, you'll see the Tyrannosaur wishbone on that. I mean I wouldn't want to try and take one of these things down and then break it for good luck, but you know, it's still there.

FLATOW: Yeah, that's quite interesting. OK, let's go over here now.

UNIDENTIFIED MAN: Yeah, I've got a question, but I want to tell you a quick little funny story about the brontosaurus, Apatosaurus. My daughter was three years old, and she was in preschool. They went to the post office for a field trip, and when they went there it was just as all the dinosaur stamps had come out.

And the postman there was telling, oh, here's Tyrannosaurus, Triceratops, and oh here's brontosaurus. My daughter goes: No, that is an Apatosaurus. They put the wrong head on it.

(LAUGHTER)

UNIDENTIFIED MAN: So yeah - and so the postman looks over at the teacher, and she goes: I don't know.

FLATOW: Where did that come from?

IRMIS: Kids are on the ball.

FLATOW: That's a great story. Do you have a question?

UNIDENTIFIED MAN: But the question is, is - you know, we know the asteroid came in and basically ended the reign of the Cretaceous, but the species of the dinosaurs seem so different between the Triassic, the Jurassic and the Cretaceous. Was there some other extinction even in between those too?

IRMIS: There are a number of different extinction events, and, you know, we think about the age of dinosaurs as a single, monolithic thing. But if you think about a timeline, Tyrannosaurus rex being 65 million years old, and the first dinosaur being 230 million years old, Tyrannosaurus rex is actually closer in time to us than it is to the first dinosaur. So there's a lot of change that happens in the middle there.

And one of the reasons dinosaurs became so successful is a mass extinction event at the end of the Triassic, at 201.5 million years ago.

FLATOW: So did they go from being small up to the largest ones at the end?

IRMIS: They did increase in size. Most of the Triassic dinosaurs are pretty small. There's a few that got larger, but they were just one of many reptiles at the time, and it took an extinction event to clear out the ecosystems for them to become successful.

FLATOW: And the extinction event allowed mammals then to flourish?

IRMIS: In part - that's - the one at the end of the Cretaceous did, yeah.

FLATOW: Yeah, terrific. Yes, step up to the mic.

UNIDENTIFIED MAN: I'm wondering: I know we have some general ideas about like the musculature of the dinosaurs by, like, muscle scars, I think, they're called. But I'm wondering what - how much do we have to infer about their behavior and their physiology? Because a lot of it just does not, you know, fossilize, and how much - and what - I'm basically wondering if there's kind of a limit to what we can figure out about these animals without using analogs to modern-day...

FLATOW: Yeah. We have to guess a lot.

BRITT: Modern animals are the way we figure out a lot of these things, where the muscle scars all are. All tetrapods have the same series of bones, basically. And you can look for the muscle scars, though muscles vary from one group to another. But we also use things called phylogenic bracketing, where we look at - OK, we say here are dinosaurs. Here are their - birds are their descendants. We get insights from them. And then on the other side, we can look at some of their distant relatives, such as crocodilians, which are orcasaurs, and we look at their lung structure. And we learned that even - we just recently learned here at the University of Utah that the orcasaurs and the crocodilians actually have a single, unique lung that allows the air to flow only in one direction through it. Just like a radiator of a car, the gas is passed only one way. So we can learn a lot by looking at the present. Likewise, we can learn about the present by looking at the past.

FLATOW: But how much can we tell about what the color of the skin, or what it looked like? Is that preserved at all, the color?

SWITEK: Well, for feathered dinosaurs, it is. I mean, that's been one of the things I heard as a kid all the time, as that we'll never, ever know what color dinosaurs were. And I used to, you know, draw these really garishly colored awful, awful dinosaurs - purple and fire engine red and everything else. They're actually colored a lot more like ravens and magpies that you might just see right outside. The way that this is done is through microstructures that are within feathers, and these are modern bird feathers, as well, called melanosomes.

And they help create colors like black and brown and red and rust colors like that. So there's a structural basis for color in these feathers. By looking for the same structures in fossilized dinosaur feathers, paleontologists can sort of reverse-engineer what colors they were. So they've only done this for a few so far. But, yeah, the little feathered dinosaurs that they've been able to accomplish this with, they don't look at all much different from the raven that you might see on the side of the highway.

FLATOW: Mm-hmm. Well, let's go to the audience. A question right there. Yes. Go ahead.

UNIDENTIFIED CHILD: How deep do you usually have to dig to find bones?

IRMIS: Well, we start out on the surface, because that's where we can actually find the bones coming out of the rock. But sometimes we have to dig really, really deep, depending on the angle of the layers and stuff. I've seen - we've had a few digs where we had to remove something like 20 feet of rock from above the layer where the bones were.

FLATOW: Wow. Let's go up there to the balcony. We've got a question up there in the balcony.

UNIDENTIFIED CHILD: I was just wondering: What was the, like, most amazing find you or one your colleagues has found in Utah. And why, I guess?

FLATOW: He wants my job, this kid.

(LAUGHTER)

FLATOW: That's a great question. That's a great - who wants to answer that?

SWITEK: Well, I'll jump in first, because I haven't really found anything. I found a little old lizard track in Dinosaur National Monument, in the Triassic rock. And I brought it to Randy, because I was out with his crew, and he said: Where's the rest of it? So I'm still working on it, and I will try not to disappoint you this summer.

FLATOW: Let me remind everybody that this is SCIENCE FRIDAY, from NPR. I'm Ira Flatow, here with Randall Irmis, Brooks Britt and Brian Switek. All right. The other two, what would be your key find, the one you like the most?

BRITT: It's usually whatever you're working on currently. And one that we're working on now is not even a dinosaur. It's what we call a drepanosaur. These are crazy-looking little things that look like they're designed by some type of committee, and it has a head of a bird. It has the arms of a - and shoulders of a mole. It has an elongated neck that we think maybe had folded itself up like a Z. And the tail was elongate and prehensile, like wraparound branches, what have you. And they had a claw at the end of the tail.

FLATOW: Wow.

(LAUGHTER)

FLATOW: Wow. A claw at the end of the tail.

BRITT: It might have been a nightmare, but we think we saw that in the lab the last couple of years that we've been studying this.

(LAUGHTER)

FLATOW: Randy?

IRMIS: Well, I'll stay in the Triassic period, and probably my favorite find was something I found as an undergraduate at Grand Staircase-Escalante National Monument. This thing called Poposaurus, which looks like a miniature Tyrannosaurus rex walking around on two legs, has a big carnivorous skull on it, but it's actually more closely related to crocodiles than it is to dinosaurs. So there's all sorts of experimentation going on and really weird creatures back in the Triassic.

FLATOW: Really weird. Yeah. Yes. Go ahead. I didn't mean to say weird and point to you.

(LAUGHTER)

FLATOW: That's OK. I'm sorry. Go ahead.

UNIDENTIFIED CHILD: Why do lots of dinosaurs' names end in saurus?

FLATOW: Oh.

SWITEK: Well, part of that's tradition. So, in 1842, there's a British anatomist named Richard Owen, and he coined the term dinosauria. So ever since then, that's kind of been the traditional way to do it. They seemed, you know, to be reptiles. Back then, they thought they're very much like lizards. So it just kind of stuck, and, you know, it sounds nice. You know, like the name Tyrannosaurus, that's one of the best names ever coined by anyone ever. So it sounds good. You know, put it after almost anything. If I could be, you know, Brianasaurus, I totally would.

(LAUGHTER)

FLATOW: Wow. I think we have one more - I guess you have a question here.

UNIDENTIFIED MAN: (unintelligible) Utah's interesting geographical landscape. It has an interesting political landscape. And I know right now there is movements for federal lands to get moved into state lands, and also oil industry to move in. Talk to me a bit about what you guys' impression of that. Is there concerns in that area?

IRMIS: Well, all of us here at the table do work on public lands. That's where we are finding our fossils, because they're protected. We can get research permits. And then everything is held in the public trust in museums. And for private land, that's not necessarily the case. But we have very good laws both for state land, as well as various different types of federal lands here, here in Utah.

FLATOW: Anybody want to add anything to that?

SWITEK: Yeah. And I'm not opposed to development on private lands, because sometimes we have bones exposed that way.

FLATOW: Yeah. Quick question up there in the balcony.

UNIDENTIFIED CHILD: In the "Jurassic Park," movies, it seems as if the dinosaurs could talk to each other. Is a dinosaur was of the same species, could then talk to each other?

SWITEK: Well, they could communicate much the way that animals do today. I mean, we can't always tell what sound a dinosaur would make. But for a particular group, this group of so-called duck-billed or shovel-beaked dinosaurs called hadrosaurs, they had these big, funky crescents on the back of their skulls. And these crescents are hollow, and people have actually reconstructed what the sound is like. It's kind of like a foghorn, or like a semi-horn. And these dinosaurs also had inner ears that were attuned to this kind of sound. So they're calling to each other over long distances, these little frequency sounds, sort of like what elephants make today, to communicate with each over long distances. So with those sorts of fossils, we can tell. But otherwise, it's really hard to figure out what a dinosaur would have sounded like.

FLATOW: Well, I want to thank you, gentlemen. We've ran out of time with this segment. We had such a good time. We learned a whole lot. Thank you, gentlemen, for taking time to be with us today. Randall Irmis, curator of paleontology, Utah Natural History Museum.

(APPLAUSE)

FLATOW: Brooks Britt, associate professor at the Department of Geological Sciences at Brigham Young. Brian Switek, science writer. His new book is "My Beloved Brontosaurus: On the Road with Old Bones, New Science and Our Favorite Dinosaurs." It's a really good read, I suggest you all. Thank you all, gentlemen, for taking time to be with us this afternoon.

SWITEK: It's been a pleasure.

(APPLAUSE)

FLATOW: We're going to take a short break, a couple of seconds. When we come back, we're going to take a trip to a new world, Mars. We'll look at Mars by looking at Utah's desert. We're going to be talking about Mars. Stay with us. We'll be right back after this break.

(SOUNDBITE OF MUSIC)

FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR. Transcript provided by NPR, Copyright NPR.

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