Episode 454: Tyrannosaurus with Pete Larson — remastered. We went back and remastered our first ever episode of I Know Dino so that the interview is a lot easier to hear and understand.
The dinosaur of the day: Tyrannosaurus
Pete Larson, paleontologist and president of the Black Hills Institute in South Dakota. He led the excavation of the T. rex named Sue, the largest and most complete T. rex found at the time. Pete is a T. rex expert, and one of the main people in the documentary Dinosaur 13:
When Paleontologist Peter Larson and his team from the Black Hills Institute made the world’s greatest dinosaur discovery in 1990, they knew it was the find of a lifetime; the largest, most complete T. rex ever found. But during a ten-year battle with the U.S. government, powerful museums, Native American tribes, and competing paleontologists they found themselves not only fighting to keep their dinosaur but fighting for their freedom as well.
In this episode, we discuss:
- Pete Larson, paleontologist and president of the Black Hills Institute of Geological Research in South Dakota. He led the excavation of the T. rex “Sue,” the largest and most complete T. rex found at the time.
- The documentary, Dinosaur 13, came out recently about the excavation, detailing the federal government’s seizure of Sue, the 10-year long legal battle, how Black Hills came together to fight for Sue, and Larson’s 18 months in prison.
- The dinosaur of the day is Tyrannosaurus rex, which is ancient Greek for “Tyrant Lizard.”
- T. rex lived during the late Cretaceous period, in western North America (at the time an island continent called Laramidia)
- T. rex was one of the largest known land predators; up to 40 feet in length, 13 feet tall at the hips, and 6.8 metric tons
- T. rex was probably a predator and a scavenger, and was estimated to have one of the largest bite forces among all terrestrial animals
- Scientists used to think T. rex walked upright and dragged its tail (a “living tripod”) but now they think the tail as off the ground, as seen in Jurassic Park.
- Henry Fairfield Osborn, the former president of the American Museum of Natural History, was convinced T. rex stood upright and unveiled the first complete T. rex skeleton this way in 1915. It stood in this upright pose for 77 years, until 1992.
- T. rex probably had feathers, at least on parts of its body.
- T. rex had enhanced eyesight, hearing, and sense of smell (comparable to modern vultures), and could track prey movements from long distances.
- T. rex may have had pack behavior.
Garret: Yeah, when we were in Dinosaur National Monument, which is this really neat museum that spans the Colorado-Utah border, they have a couple points where they talk about dinosaurs with feathers and I like to imagine the T. rex being covered in black feathers and looking like a giant evil raven or something like that. And I can imagine that being much more terrifying with its ruffled feathers and looking that much bigger than if it was just a scaly, green creature.
Sabrina: It would be terrifying.
The time between when Stegosaurus lived and when T. rex lived is longer than the time between when T. rex lived and now.
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For those who may prefer reading, see below for the full transcript of our first episode (including the interview with Pete Larson):
Garret: Hello and welcome to I Know Dino. I am Garret.
Sabrina: And I am Sabrina.
Garret: And we are dinosaur enthusiasts, we want to share our love of dinosaurs with everybody and talk about some fun dinosaurs facts, interesting things that are discovered as they are discovered. So, today our topic is going to revolve around Tyrannosaurus rex, one of the most popular dinosaurs in modern culture.
Sabrina: So, we had a chance to interview Pete Larson, a paleontologist and president of the Black Hills Institute of Geological Research in South Dakota, which Garret and I were lucky enough to be able to visit when we drove across the country. And Pete Larson led the excavation of the T. rex Sue, which is the largest and most complete T. rex found.
Garret: Interesting thing about the Black Hills Institute, when we were driving through South Dakota, it was actually during the Sturgis Motorcycle Rally and we had to park several blocks away from this place and you were walking down the street and you were looking for a museum, you are expecting a large building and I don’t know maybe some columns or something, at least a big sign. It is a very unassuming building, it used to be I think a gymnasium and you go in and it was like stepping into a different world from this crazy biker rally.
Sabrina: So even though it was a small institute it was full of a ton of fossils and very helpful people willing to talk about dinosaurs all day long. I highly recommend going there if you get a chance and you are in South Dakota.
Garret: We were pleased to find out that some of the most well known T. rex fossils were found in the area around this Black Hills Institute in South Dakota, Wyoming and they actually still have one on display there, which is really neat.
Sabrina: And now here is our interview with Pete Larson.
Sabrina: How did you decide to become a paleontologist?
Pete Larson: Well, I guess I was fascinated with fossils since I picked up my first fossil when I was about four. And it was a tooth—It was obviously a tooth, but it was black. Why was it black? [LAUGHTER] And so I went into the local museum and a gal there by the name of June Seidner [ph] who—She and her husband own the museum—kind of took me under her wing and started teaching me about fossils and loaning me books, and I was hooked. It was all over from them on.
Sabrina: What is it about dinosaurs that you think fascinates you the most?
Pete Larson: I think paleontologists have what we call—what I like to call a Peter Pan syndrome. We never really grew up. We’re still those little kids who are fascinated by dead things and by things that have been dead for a really long time, things that were real and truly—really and truly monsters. Fossils are fascinating, but dinosaurs are even more fascinating. There’s just something so strange for the imagination because there’s nothing really like them living today. We have some of their descendants in birds. There’s no bird that weighs ten tons. There’s no—They just don’t—They don’t get that big anymore. And I think that—once you start getting into it, it’s just that fascination with the world as a different place. We become time-travelers. We look at things in a way that kind of opens our imagination in a way that very few other sciences allow you to do. Now, of course, there are things like astronomy where you can imagine what it’s like to live on another planet. But the cool thing here is that we don’t always have to use—It’s not just all imagination. It’s—We have tons of evidence and lots and lots of places in the world where we can go and see that ancient life, in what remains in what we call fossils. So I said that for me, at least, it’s that fascination and looking at things like a kid. I mean I just—I never grew up. I’m a very lucky person.
Sabrina: [LAUGHTER] And what are some of your favorite types of dinosaurs? Do you have any favorites?
Pete Larson: Well, of course, T. rex. [ LAUGHTER]
Pete Larson: T. rex, Tyrannosaurus. Because that’s what I study. Fossils are some of the most fascinating very early [INAUDIBLE] animals with these little cute arms and big leg muscles that allowed them to run really fast, and these giant teeth that wouldn’t necessarily have to take bites out of everything. He could swallow quite a bit of stuff just whole. [LAUGHTER and INAUDIBLE] And I mean just—They’re—Just about the biomechanics of this animal that is like nothing that’s really on earth today to try to understand how it would—How fast it would—How it would capture its prey. Behavior. We have some hints and clues in the fossil record. We have scars on the bones where tendons attached muscles to bones, and we can follow those back by looking at modern animals so that we can get some kind of an idea of biomechanics and physiology of these animals. But it’s still a lot of theorizing and even speculation that goes into it and this sort of thing. So it just—I don’t know—It just keeps you thinking about things that normal world doesn’t do in a way that these animals have so many of unanswered questions. I think that’s what keeps finds going, unanswered questions. Maybe we can find the answer to this question. And then, of course, once you find the answer to that question, it raises ten new questions. So it’s a never-ending sequence that gets played out, which is just wonderful.
Sabrina: So you don’t think that all the questions will ever be answered?
Pete Larson: Well, it’s is not exact. Especially in observational science. In observational science, not—Unlike mathematics where we do know what the square root of two is because we invented mathematics—But unlike math, although we [often mention?] mathematics in our observations as well observing the natural world, but still I thought, for instance, that we could determine—There must be a way to determine the sex of a dinosaur. And I was particularly looking at Tyrannosaurus rex. I came up with an idea. [INAUDIBLE] work by other people like Alfred Sherwood Romer and other people who had looked at modern animals, crocodilians, lizards, mostly crocodilians, and had noticed that there seems to be a difference in the shape and placement of the first chevron, the first U-arch which is a bone that is on the underside of the tail. The first one, which is one closest to the pelvis. When was that, I did a little bit of—With a few specimens we have, which was basically there was one specimen, now it’s two—And looked like its shape was like mole, but—Two more specimens have been found and me using that and actually publishing on it—When you present a theory—A hypothesis and then you turn it into a theory and you present that theory to the scientific community. The scientific community then, their job is to falsify that, to see if it is—If they can make it as incorrect as you can. It’s almost impossible to say something is truth. We approach the truth. But it is possible to say, ‘That does not work.’ So a colleague of mine, Bern Gerrigson [ph], and one of the students looked into this and then invited me on a project. As it turns out, my original hypothesis was incorrect. The chevron shape and placement have nothing to do with the sex of the animal. It is somewhat random, so it probably wouldn’t work with dinosaurs as well. Our model there were Alligator mississippiensis, greatest [INAUDIBLE]—Easy for him, he has lots and lots of skeletons that have different sex. But there are other hypotheses I’ve been working on. One is that—One thing I proposed quite a while ago and Mary Schweitzer actually proved was that medullary bone is sometimes preserved in the fossil. Medullary bone is present in today’s birds only in females and only during ovulation. It is bone that is deposited in a very loose network within medullary cavities, things like the femurs first. That bone is used—The bird uses that when it’s creating egg shells. Egg shells are calcium carbon, so it takes in bones hydropolapotatis [ph]. It’s a good source of calcium. So she was actually able to find stuff on Tyrannosaurus rex, interestingly enough, that had medullary bone within the cavity of the femur. It matched the medullary bone in extant birds, and she proved that one was female. And from there—I used that information looking at—I just had information to progress another part of my hypothesis which was that birds—meat-eating dinosaurs—Dinosaurs and Triceratops and their living relatives, birds, have similarities. Any birds have—You can actually weigh an adult bird and find out what sex it is. It’s called sexual size dimorphism. Now, sexual size dimorphism may be in the case of something like an ostrich where the male is larger than the female in the same thing. Or it may be, as in the case of Anseriformes, which are ducks and geese, and almost all birds of prey, it turns out that the female is the heavier and the larger of the dinosaurs. And my speculation was that like birds of prey, theropods, the female was probably just more robust form. To test this, I measured the length and circumference of the femur and plotted it on a graph: so there one axis is the length of the femur and one axis is the circumference of the femur. And T. rex and a number of other at least Tyrannosaur theropods plotted out two divergent lines. So as the animal reaches maturity, they go into two different lines where you have one that has a femur increased in length and one gets a much bigger girth. And my hypothesis was that one was a bigger girth was a female. And when I plotted specimen that Mary Schweizer was able to show had a medullary bone, it plotted in with more robust forms, the bigger ones. So the biggest—This was my theory from that then is that the biggest and baddest of all T. rexes were females. And so—[LAUGHTER]. Sort of show you the line on reasoning that goes in. And so the way to falsify that then is to find one medullary bone that’s in the graphil [ph] group. There’s other circumstantial evidence that makes me believe that, including the types of injuries to the tail, the tails of Tyrannosaurs are these robust forms always seem to have injuries right at the base of the tail which is possible during copulation because these are big animals, there can be ligament tears, there can be broken bones, there can be a number of different things that can happen. So that also fits in with that pattern. There’s a couple of other things I’ll be looking for details that also fit in with that pattern.
Sabrina: Yeah, I have a few questions about T. rex since you’re a T. rex expert. So I’ve read a few different things. Some people think T. rex is more of a scavenger and others think he’s more of a predator.
Pete Larson: Well, they are both right. Large-bodied carnivores are, for the most part, there are very few obligant predators. Most of them will scavenge. When you get a free meal, there’s no sense risking. Half the time when you’re hunting something, you’re taking a big risk of injury. And a big risk of not success—Of not being able to be successful on your hunt. So things like lions, hyenas, bears, dogs, all—The whole group—Every—All birds of prey, which includes, of course, vultures, and that would—Which have been—Anyway, they’re actually a group of storks, many, many other birds also scavenge who would actually hunt as well. The reason I think that—We have good evidence to support that they did hunt. We have specimens that got away. A number of [INAUDIBLE] dinosaurs and a number of triceratops that show heel injuries that could only be inflicted by Tyrannosaurus rex, including a relatively recent specimen which Robert D. Pullman, myself, and others described recently. It was a fossil where there was two [INAUDIBLE] tail vertebrae that had fused together and in fu—Within that fusion, there was a broken [INAUDIBLE] rectitude that could have only gotten in when the animal was alive. Why? Because that injury was healed, so it got away. It got away. And unless somebody walked up to—As Jack Horner suggested, well, T. rex probably just walked up to it and thought it was dying or dead and was actually asleep, and it bit, and it ran away—Unless you have something— Rather silly explanation for that. And there’re—It’s multiple evidence. That’s one reaction to [INAUDIBLE] too significant. But there is multiple evidence of injuries, healed injuries that seem very clearly inflicted by the bite of the Tyrannosaurus rex. But so there’s—Another bit of evidence, there are no large-bodied obligant scavengers existing today. Why would we think there would be some in the past? There are only a certain number of niches, biological niches, that can be filled. On land, the only—The closes thing to obligant scavengers we have is a group called vultures which are related to storks and not related to eagles and stuff. Well, they’re related to eagles because they’re birds and stuff. But vultures—But even vultures, when they’re hungry, they’ll kill things. And the argument was made that while vultures have a really—An extremely good sense of smell—Actually, no bird has a really good sense of smell—The Turkey vultures are really the only vultures that have a good sense of smell. But we don’t—You don’t need a good sense of smell to smell that something’s dead. And most scavenging occurs before the carcass is rotting. So that’s kind of not a very good argument that just because T. rexes have a really, really excellent sense of smell. Dogs, on the other hand, have probably the best sense of smell of any mammal, the group called dogs. And they use that sense of smell to hunt prey. They also love to roll in dead things.[LAUGHTER] And things like hyenas which are thought to have been scavengers actually kill more their prey more even than the lions do. So there is no [INAUDIBLE] in scavenging in any extent forms. So why would there be in fossil ones?
Sabrina: Right. That makes sense.
Pete Larson: And when you say T. rex and all their kin, so all of those animals, they’re all scavengers? I don’t think so. There wouldn’t be enough stuff to eat if they just waited for them to die. When you’re hungry, you go out and kill something. They did—They would scavenge. There’s no reason to assume they wouldn’t scavenge. But did also—They were also active predators.
Sabrina: Did they tend to stick together in groups or were they more solo?
Pete Larson: We have—For T. rex, we have some evidence. Some of their relatives, they’re called Albertosaurus on Dry Island in Alberta, they found evidence of eight of those animals together. That’s a Tyrannosaurus closely related to T. rex, a little bit earlier, a little bit smaller. But with T. rex, we also have—There’s—There are three instances where more than one—Parts of more than one—Actually, four—Three—Four instances where more than one individual has been reported found together. So it seems likely that they perhaps travelled in group, whether it was a family group or something of that order. We don’t know. I expect it might be a family group. Some smaller groups, not big groups. And other evidence for other Tyrannosaurs, like Nanotyrannus, we find sites where there are 30 or more Nanotyrannus teeth at one kills site or feeding site. And one animal couldn’t lose 30 teeth in one feeding.
Sabrina: What’s a typical day like for you?
Pete Larson: Summer or winter? In the winter, I’m usually in the lab and mounting dinosaurs, ordering the office, working on contracts. Also, we do—We used to do a number of trade shows, we’re kind of down to one now, so it’s just a general [member?] show we do. We’re there for about two weeks and we set up an exhibit, talk to people, and sell stuff, that sort of thing. So—In the summer, I’m out in the field a lot. So I’m looking for dinosaurs, as well as digging them up.
Sabrina: So I have a couple of questions about the Black Hills Institute specifically. I know that you guys are responsible for probably most of the T. rex casts in museums around the world. So what are some of the more famous ones?
Pete Larson: Let’s see. We have—There’s one in the Smithsonian Institution. There’s—We have one at Manchester University. We have a number of different museums in Japan. We have—There’s like—I’m trying to remember—More than 50 skeletons. [INAUDIBLE] skeletons 50 or so? More? 50 plus. Plus then we have several skeletons of T. rex called Bucky. So Stan and Bucky are the two. We have—There’s Children’s Museum in Indianapolis, Houston Museum of Nature and Science. There’s some English ones—My brain isn’t working too well today. But we have one in Spain, we have one in Italy, and there’s one in Leighton, Holland. There’s a couple in Korea also. At least one is Seoul, Korea and then another—One or two. There’s one in the—There’s one or—There’s two actually in the National Museum in Tokyo, National Museum in Japan. There’s one in the [INAUDIBLE] Prefectural Museum, there’s one in Kuli [ph], there’s one in Osaka, I believe. There’s—Just kind of all over. [INAUDIBLE] big skeletons.
Sabrina: Do these museums contact you and say, ‘We want a cast’ or how does that work?
Pete Larson: Pretty much, yeah. Through word of mouth. Or we have a website, too, bhigr.com. And we—So it’s mostly word of mouth. So museums find out about us.
Sabrina: Is the museum making these casts pretty regularly?
Pete Larson: Yes. We have, right now, something around 20 some people. We had as many as 35, maybe more. And it depends on the last—The last recession kind of cut—We had to cut back a bit, but things are getting better now. And so we’re doing—Even now, we’re doing several T. rex skeletons a year. We’re just doing one now for a museum in China.
Sabrina: What’s the process for creating a cast?
Pete Larson: The process is—Of course, you have to have a skeleton to mold. So first of all, you have to prepare a T. rex skeleton and then create the mold so you can make basically clones of the bones. Those molds, you have to pour cast. And we use [INAUDIBLE], foaming and non-foaming resonance. So they’re plastic. We also have to create internal fill frameworks. So there’s drilling, sometimes cutting of the cast bones which allows to put these fill in to support the bones. And then in order to—There’s a design phase where you work with the museum that comes up with the pose and we make sure that it is—We do the engineering of it, but they try to come up with an idea for the pose which we either suggest few different possibilities or they come up with something that we work together to make sure that it is physiologically possible for the animal to do it there—What they’re asking. And then the mounting takes place where we create that armature. Each of those mounts need to be done in a modular fashion because they’re mounted here at the Institution and shifted [INAUDIBLE]. Once they’re done—Once the mounting is done, we have to do some—Basically, filling of places where we’ve had to cut the bones apart and just basically, kind of making it look nice again in so there’s no screws. And then the entire specimen is painted to look like the original bone. And then the specimen is crated, which is also—We have to create brackets, mounting brackets for each of the pieces, individual pieces of the dinosaur that are then put in crates and the crates are shipped out. And then we have to create a video. Most of museums are able to mount them themselves. Sometimes they ask for one or more of us to go and help, but usually it’s pretty straightforward and they can actually put them together. If we do a mount, once we have a specimen in the museum and uncrated, usually it takes about an hour to put it up.
Sabrina: What happens once you’ve made the mold with the actual bones? What happens to the real bones afterwards?
Pete Larson: The real bones for Stan are in a museum here. Like I said, we have a museum where that’s the original Stan exhibit for people to come to see. The original of Bucky was sold to the Children’s Museum of Indianapolis, so they have the original in Indianapolis, a full fossil for people to see. So the original is eventually mounted and—We also have another [INAUDIBLE]. So the original—We show cast and the original is in a museum in Houston.
Sabrina: So going back to T. rexes real quick, what kind of parent were they? I know—I heard—Or I read somewhere before that Triceratops may have attacked the babies, so maybe as a result there were more nurturing parents? But—
Pete Larson: If we look at birds of prey. That’s probably the best example. Birds of prey will take care their chicks up to a certain point. It’s a very strenuous part of their life, which is why it takes both of them to do that and which essentially finding multiple—Sites of multiple T. rexes, I take it there’s good chance that they also had parental care and they stayed together because of that parental care. There’s no—And we also had found smaller—Parts of smaller T. rexes with the bigger T. rexes, which shows that they were at least together during their time of death, which indicates that they potentially, very likely were together as they died together as well. So it’s—I think that had parental care. It’s something that’s very difficult to prove conclusively, but there’s some circumstantial evidence that indicates that they probably did have some sort of parental care. Plus, meat-eating dinosaurs, theropod dinosaurs, the ones where we found [INAUDIBLE], we also found some instances parents fitting, incubating the egg, sitting on the nest. So that’s parental care before birth also.
Sabrina: Just theropods? No other types?
Pete Larson: There’s some indication that other groups perhaps had parental care as well because of how [INAUDIBLE] hanging around their nest for a while. But that’s Jack Horner stuff. Subject Jack Horner is working.
Sabrina: How do you feel about movies that feature dinosaurs in them, like Jurassic Park and [INAUDIBLE]? Is there a lot of stuff that’s kind of inconsistent with what science’s found to be true?
Pete Larson: Well, movies are movies. I love the fact that we can look at these animals as living individuals. Movies are able to recede the eye [with this?] the most convincing and, I thinking, very realistic, yet very powerfully mimics what the dinosaurs themselves were like. Which, again, that’s the Peter Pan syndrome.
Sabrina: Let’s see. For Triceratops. I had—I know there’s been reports that maybe it was actually a juvenile Torosaurus? Is there any evidence yet of—If it was an actu—
Pete Larson: [CROSSTALK] There’s a number of papers now, a lot of people are working on this. It was a good question. It’s always good to ask a question. That’s what a possible scenario—Propose a hypothesis. So Jack Horner and John—Scan—Scan, what’s his last name—Anyway, what they proposed was quite a probable scenario that definitely needs to be invistigated. I think I do not agree with their conclusion. I don’t believe that a Torosaurus was actually an adult Triceratops Hornus. There’s a lot of reasons for that, many of which are published. We collected a lot of Triceratops. And Toros—Morphology of Torosaurus is very different from the skulls—Very different than the skulls of Triceratops. They only get big Torosaurus, more or less, but there they are. Partial Torosaurus are much smaller. We have a semi-adult here. It’s about—A little big bigger than a standard full adult triceratops hornus. Triceratops hornus is a much smaller size, has a very coarse and rough texture to the bones. Younger ones are smooth. Torosaurus is—The [INAUDIBLE] texture of this Torosaurus skull—By the way, adult Torosaurus skulls do the same thing, they get that very coarse texture. But this particular Torosaurus skull, which [INAUDIBLE] as opposed to normal six-and-a-half foot long normal Triceratops hornus skull. Very smooth texture. There’s lots of [dirty?] detail. Characters. Anatomical differences that separate them, including the shape of the muzzle, shape of the nasals, premaxilla, very different premaxilla. Just a number of characters—Just—You have to change all this stuff. And why do you have this adult texture on these animals which are supposedly still growing and are going to grow another—The biggest Torosaurus skull is like nine feet long. It’s huge. Whereas Triceratops only gets to be six and a half—Maybe might make seven feet long, but I’ve never seen quite so [INAUDIBLE] Triceratops. So—
Sabrina: I know you were part of a dig that involved—What is it, three Triceratops in Wyoming last year?
Pete Larson: There-s—Yeah, there’s actually four. Going back to the site, we—It’s a big site, so we’re unable to get it finished, plus we had a T. rex to dig and stuff, so we were unable to do as much stuff there as we had hoped.
Sabrina: So you have to wait until summer?
Pete Larson: [CROSSTALK]—Back out there. We’ll be back out there in May.
Pete Larson: It’s interesting because there’s really no—These animals, because of some partial articulation in things, the bones are very concentrated within an area that’s three meters long and at least 20 meters wide, there’s a part that’s 30 meters wide also, maybe bigger. They obviously died together as they lived together. Triceratopses are known—Triceratopses have been know usually for the fact—Up until this time, only single specimens. There had been a couple of occurrences where through stream aggregation, through just high accumulation of bones, there’ve been parts of more than one found in certain areas, but they were not anywhere near complete animals and were pretty clearly washed into place. That—So that we can’t fake that they lived together. So most thought that triceratops was an isolated type that lived by itself. It’s just so interesting because there’s four different sizes, two adults ones, just a little bit smaller than the other, two sub-adults, almost—You can almost call them juveniles, smaller ones. Those animals represent three different age groups. So what were they doing together? I don’t know. But it raises some possibilities. Maybe family group for protection. Because if you have more than one Triceratops, that’s just so wonderful. [INAUDIBLE] people. You got T. rexes and they form circle and they pull [INAUDIBLE] into circles and ward off T. rexes. One possibility. There’s safety in numbers. I don’t think they ever formed very large herds because we had seen bones beds, like some of the ceratopsian in one beds of Canada and then [INAUDIBLE] bone beds from Canada and here in the United States and other places. [INAUDIBLE]—Where we have hundreds and sometimes thousands of individuals together. [INAUDIBLE]—Triceratops which seems unlikely they were part of one heard. But these animals are different. Sort of brand new bit of information which changes our ideas on what Triceratops were like.
Sabrina: It seems like a lot of perceptions of how dinosaurs behaved and even looked like and stuff have changed a lot in the last 10-20 years. Does that—Is it always changing so much?
Pete Larson: The change that happened in the last 20 years, I think, was brought about by interest in dinosaurs the last 20-30 years [INAUDIBLE] Back in the 70s—Actually, it’s probably 40 years, the last 40 years, we’ve had a dinosaur renaissance. This has been fed by the movies. Movies have kept the public interested because of public’s interest in [INAUDIBLE] scientists who make discoveries to let the public know that those discoveries are being made because it helps the interest in dinosaurs go on. Because of that, people are more likely to actually get out in the field and want to make some discoveries. The museums are very interested in their staff. There are some instances to have it staffed to try to get some publicity, get people come see them, so they want to have dinosaurs coming there, which is what helps our business, of course. But it also means that scientists—Because the interest in dinosaurs is up, scientists are able to get funding for their work. And so this is a really good thing. The Jurassic Park movies have been good for everybody. Not only does it give people like me, give people like me the opportunity to see the dinosaurs in the flesh, so to speak, not just in my mind, but on the screen. It gives the public that opportunity. And because the public has that opportunity, they’re able—Or, they keep their interest because there’s something knew they’re learning. So we have places like Liaoning, China, this wonderful late deposit which has produced all of these feathered dinosaurs and just double, in some ways, a lot of the information on the ecology that the animals were around at the beginning of the Cretaceous. So they both feed each other, and the more discoveries are made, the more money is available for the discoveries, which makes then discoveries more possible to be made. And because there’s so little we know about these animals—We have thousands, and thousands, and thousands of dinosaur species that have yet to be discovered. There are times when—Geologic times that are not well preserved in the fossil record or preserved in areas that are very remote that people have not yet explored. So everybody—Paleontologist wants to be making discoveries to help justify your existence, to help bring in funding and help get back in the field again. So all of this is not just self-serving, it is self-feeding and it is self-perpetuating. It is something that allows us—These businesses of finding dinosaurs and describing dinosaurs, putting dinosaurs in museums, it helps to fund that.
Sabrina: So what is a typical dinosaur dig like?
Pete Larson: Not like Jurassic Park. So typically you’re away from—You’re camping out because—Not only because it’s just nice to get out and camp out. But you’re camping out because you’re away from town. You’re out in [INAUDIBLE], out in the Badlands, out where the ground is [INAUDIBLE] in a country like Mongolia. You have to take all your stuff with you. You can maybe make a trip into town every once in a while, but you can’t go every night and have—Stay at a hotel and have a dinner at a local restaurant. There’s some people who do that, but it gets expensive. And besides, it’s much more fun to just be out in the field. So we seem to get up early, we may have to knock off during two hours in the afternoon because it gets too hot because out here in the West in the summer, it can easily be over 100 degrees. We have bad storms that come through. We have most of our rains and thunderstorms—Moisture from thunderstorms. It can go right past, it can go right through you. You have sometimes very little time to cover up your site. Sometimes it’s not [invitable?] to cover up the site either. But you can be rained in. We have—Especially working in the spring, you’re rained in for days at a time where you can’t do anything. You’re lucky just to have cell service. In the old days we had no cell service, of course. But not all of our sites—Most don’t have cell service and we have to go up on top of a hill to make phone call. Which is OK, being away from the telephone and computers can be a really good thing after a while.
Sabrina: So how do you determine where to dig?
Pete Larson: You have to see something on the surface. There’s—You can dig a hole anywhere you want, and the chances of finding a dinosaur bone are about as close to zero as anything can possibly be, even if you’re in the right kind of rock. So you have to see something exposed on the surface. And that in the [INAUDIBLE] formation where we were, chiefly tiny fragments of bone which vary from the rock and [encouraged?] by color and texture. Usually. If they don’t vary, you’re not going to see them. And so then you have to be able to identify what you’re looking at. Especially –It’s almost always just fragments. What kind of animal it’s from. Whether it’s a meat-eating dinosaur, [plant?]-eating dinosaur, or a dinosaur at all. And hopefully you can look at it and try—A piece that will help to tell the species or tell you that it might be something new. Then you follow that pieces back up the hill to try and find where they’re coming from. Sometimes you can find where they’re coming from, sometimes you can’t. Even if you dig a big trench, you still may not find where it’s coming from. But in the case of big dinosaurs, like T. rex, you can usually find where they’re coming from and then you begin the excavation. You look at the geology and determine what your chances are, what concealed stream flow direction to see what might have moved—Where bones might have moved and how quickly. [INAUDIBLE]—Most of the dinosaurs we find are disarticulated which means bones are not together as they were when the animal was living. But there’s so much gathered and so you have look carefully [in location?] to find an articulated—But that’s very rare. And so then you have to have a plan of digging it to take over it at first because you want to be able to move forward quickly once you start airing the bones because a lot of those bones lay out—Once their surface is uncovered, the more chance of damage of you just walking across the screen, or stumping or falling down, or cow coming at night walking across it, or a rainstorm, or just the wind blowing little pieces away. We have to glue the bones as they’re uncovered and multiple times, using [INAUDIBLE] glue and using things like [INAUDIBLE] Acetate to help create kind of protective coating on the bones. And then we dig around them and get them into smaller bundles and then put field jackets on them protecting bones [INAUDIBLE] first. And then we flip the jacks over and take them out.
Sabrina: It sounds very complicated. But—[LAUGHTER]
Pete Larson: It’s not quite rocket science, but you have to have—It takes the biggest key is experience first and recognizing what you’re looking at and figuring out how you’re going to excavate it. And having experience is the only way you can learn that. You can’t learn that at school.
Sabrina: When you go out on digs, is it typically with people who are pretty experienced?
Pete Larson: Yes. I mean we do have volunteers also. Possibly—Many of our volunteers have had quite a bit of experience. And occasionally we have somebody new that wants to learn, maybe even a Master’s student or something like that wants to come and learn how to do their job. [LAUGHTER] And let’s say, it’s a process that takes—The longer you do it, the more you do it, the better you are at it. The better you’re—The more your guesses turn into something—A reasonable hypothesis rather than just pure speculation. And so it’s like anything, the more you do it, the better you are at it. Conversely, if you have someone who’s learned in some the old school method of doing thing that are not willing to change or to try new methods. Also, it’s very important to have an open mind, to try to find always better ways to do things. And if you have somebody who’s set in their ways, they don’t make a good fossil hunter. They don’t make a good fossil digger because they’re going to make the same mistakes over, and over, and over again and not going to learn from them. So you have to have somebody who’s certain. They have to be flexible and they have to be artistic, they have to be able to—To have an imagination, to kind of project, to see underground without the aid of an X-ray or anything else like that to try to—I’m trying to find the right word here—To try to predict what they’re going to find and how it’s going to be laying. You’ll never know until you dig it up, but you can have a pretty good idea of what’s going on. If you have a you have enough experience at this. If you know what to do with each, each fossil. It’s an entity to itself and it has a certain—There are certain things about it that are unique to that fossil that you have to be able to incorporate into your understanding of what’s going on here. You want to always be watching for soft tissue preservation, which is a very rare occurrence, but it does happen. But you can miss it if you don’t have that in the back of your brain. Things like that.
Sabrina: How would you treat it if you found something with some soft tissue?
Pete Larson: You treat it differently. You don’t—The portion that shows soft tissue, you do not want to use any conservation medium on it unless there’s no other way to save it. And if you’re saving, you still—Even if you have to use a conservation media on most of it to save it, you want to make sure that there are area that you did not use the conservation media on because in order to study soft tissue, one of the things that we need to do is we need to preserve the chemistry of that. There’re still proteins that are preserved in some of these fossils that if you start adding chemicals to it, you can alter those proteins. Or you can introduce proteins. If I glue something and hold a piece of it with my finger and then I pull my finger away, of course, I’m going to leave some of my skin there. You’re adding genetic material. And you just have to be very, very cautious, in fact, even just touching things with if you’re taking samples that will be used later. You always have to look ahead—Think ahead to preserving the chemistry—The chemical integrity of that specimen as well.
Sabrina: For new species that are discovered—I guess I thought of this because I saw the Hadrosaur, the first Hadrosaur fossil found in New Jersey and I think it’s in Philadelphia, somewhere—But it was interesting because they only found a couple large bones, and yet they were able to figure out what the whole dinosaur probably looked like. So I was just wondering how do you figure that out?
Pete Larson: Hadrosaur is a full guy, which is the one you’re talking about, actually there was quite a bit there. They had a little skull, not large. But they had quite a—Certain representative bones from legs, and arms, and things, and vertebrae, ribs, and things. And of course, the original texture has been altered substantially as to what they thought. And they were comparing it to some dinosaurs that were found earlier in Europe, the Iguanodons, some of the early English and Belgian dinosaurs. But it was the first dinosaur described from North America.
Pete Larson: And if you look—It’s really fascinating to look back in the literature and look at restorations that people have done, and look at the old ancient art work and how it’s changed. You can see the advancement of science in that art.
Sabrina: I guess if you were to describe a new species today, but you only had a couple of fossils, one or two maybe, you would just base what you thought the whole thing looked like based on similar dinosaurs you already know exist?
Pete Larson: Sort of, yes. You just find a few parts and you can—In terms of the relationship of dinosaurs, it’s not a big stretch of the imagination when you use them to compare to try to reconstruct what’s the rest—it’s a Ceratopsian dinosaur, there’s some—There are many clues in the skeleton that you don’t have to have the whole skeleton before you know approximately what the whole animal’s going to look like. But you’re not going to get everything right because you don’t have enough data. But you’re going to get the general body shape, you can figure out the size, potential weight of that animal. You can figure out what—Even if you don’t have a skull, you can know approximately what that skull is going to look like, although you may—If it’s a horned dinosaur, you can choose a wrong model from the horned dinosaurs, unless you’ve got some hints as to what you’re looking at. But there’s—It’s a—That’s almost more an interpellation rather than an extrapolation because we have that tree of life which we’re constantly adding to to help us to understand the position of this particular species, the position that it sits into in that tree of life. And so that also—That allows us to then try to understand more about [INAUDIBLE] and things even because of the work that’s been done on their relatives. So there’s a lot that can be done even with very fragmentary fossils.
Sabrina: So I guess, going back to how our perceptions of dinosaurs have changed so much in the last couple decades, I’ve been reading things like maybe we could figure out what color some of them were and there’s the whole thing about the feathers. But now, there’s a recent article that I think came out that said that they were mostly scaly and only a few were feathers. What are your thoughts on how dinosaurs looked?
Pete Larson: Well, we have to go to the evidence we have. And theropod dinosaurs, probably most of them had feathers, if not through their entire life, certainly when they were young. Feather came about through insulation, were useful for insulation. It just turned out that the structure was also conducive to flight. I mean [LAUGHTER]—Flight feathers are not earlier things. We’re—I’m actually working right now on a project that [INAUDIBLE] Manchester University has joined now with [INAUDIBLE] Center where we’re looking at chemistry over the surface area over the actual element. Elemental distribution over the surface area of fossils that we’re scanning in the synchrotron there and high energy X-rays. And so we’re actually able to map distribution of elements across the face of the fossil. This has allowed us to publish on color of feathers and the color of skin in certain instances and prove that the textures or—How am I trying to say?—What we see as interns of three-dimensiality of the fossils in the microscopic level where it appeared that [INAUDIBLE] were preserved, but they looked like modern [INAUDIBLE]. And we were able to prove that they actually are. And so that actually—In addition to the work that we have done on colors just using this, it also bolsters work by other scientists who are working on that same thing. Now, Ordovician dinosaurs and Saurischian dinosaurs are quite separated from each other, and so—The only instance we have of [INAUDIBLE] having something that might resemble feathers is a specimen of psittacosaurus in China. That Psittacosaurus is a relative of the Ceratopsian dinosaurs, so it’s related to Triceratops. That Psittacosaur that is preserved there has on its back—It has a nice skin preservation, but it has apparently a rising out of little bumps on the [cult?] scales which—I guess, scales, typicals, whatever you want to call it, are these long [hair?]-like projections. We used that—We found the first triceratops skin and while we have a good portion of the skin on the entire body of the animal represented—That specimen originally in Houston, in Natural Science now—We have a lot of the skin here because we’re still looking at it, still working [INAUDIBLE]. But the skin—That skin had these bumps or almost nipple-like projections from the top surface of some of the scales. And so looking at the Psittacosaurus and looking back at the Triceratops—Triceratops could have actually had almost wheel-like projections coming out which they might have been able to raise with the muscles of their skin to make them look larger to ward off T. rex. Because obviously we only find partial skeletons ofTriceratops,Triceratops was quite tasty. Anyway, it’s—The more we, the specialists, [INAUDIBLE]. Another thing, there’s more skin and more dinosaurs than what anybody ever thought possible. People clean it away, they don’t recognize that it’s there. That soft tissue also, that—The envelope of skin probably preserves some muscle tendon and ligament evidence that we do not yet have the ability to identify. We’re close. I think that what we’re doing is something that will be able to be used for that. That’ll be part of our way of finding using the synchrotron and high-energy X-ray to map the elements. That will help us to do the biggest skeletons in finding those [INAUDIBLE]. But seeing them by eye, you’re just missing them because they’re part of the fabric of the matrix of the rock they’re buried in now. And so I think, as time goes on, that’s one of the really exciting areas is soft tissue preservation is far, far greater than what we ever thought. And preservation of biomolecules. We did the [INAUDIBLE] cells also. Very, very much—Much more of that is present than what we ever thought possible.
Sabrina: It just seems like paleontology—All this awesome stuff, and like you said, kind of get to be like a little kid. But there also seems to be a lot of controversy—With the bone wars, and then I just read about Tinker the T. rex, and of course what happened with Sue. But your passion is very obvious. And it’s really cool to talk to you about this stuff and I’m just wondering what drives you to keep on studying it despite all the battles and controversies.
Pete Larson: Well, I’m not going to let somebody’s bad behavior ruin my life [LAUGHTER]. I’m going to keep on doing what I love to do and no one’s going to stop me. There’s—Just for your information—There’s one—There’s a movie that is premiering actually Thursday at [INAUDIBLE]—Documentary on [INAUDIBLE] Sue called Dinosaur 13. That kind of—If you want—If you get a chance to see that—There’s also—We have—One of my ex-wives and I—A book called rex Appeal. That’ll tell you the whole mess about what happened. It’s an interesting story. But I have—I’m probably the luckiest person in the universe, I get to do what I love, and I have all kinds of people who care about me and support what we do, including people in museums all over the world.
Sabrina: Do you have any advice for people who are amateurs interested in paleontology?
Pete Larson: Well, I guess, pursue your loves. If you have an interest in paleontology, then you should try to find a way that you can—So that you can do it. Is there a possibility of collecting in your area, are there museums in your area that you could do some volunteering at, or are there books that you’d like to—Check and see what books are available. There’s wonderful books on paleontology, now some really fantastic dinosaur—Books on dinosaurs and that sort of thing that are there for the whole gamut of how far you are as an amateur, whether you’re a six-year-old who just picked up your first fossil or you’re 89 years old and just want to read something about dinosaurs but don’t really want to go in the field [LAUGHTER] and everything in between. So I would recommend if there’s something that you love to do, you should try to do it, whether you can do it as a hobby or as a profession, that’s up to you. But you should try to—Life is short. Life is really, really short. So do fun stuff.
Sabrina: It’s very nice. Thank you so much. It was great talking to you.
Pete Larson: It’s very nice to meet you over the phone.
Sabrina: Yeah. Nice to meet you, too.
Garret: Pete Larson’s story of how he discovered Sue along with several other paleontologists is outlined in the story Dinosaur 13 which was recently released in theaters and it details the entire excavation process, the federal government seizure of Sue which is whole another story and the 10 years long legal battle, how Black Hills came together, the city of Black Hills that is, came together to fight for her and how Pete Larson eventually ended up in prison, unfortunately.
Sabrina: And since this podcast has been focusing on Tyrannosaurus rex we came up with a list of interesting facts that you may or you may not know about this giant dinosaur.
Garret: So, starting out simply, a lot of people know Tyrannosaurus rex means tyrant lizard in ancient Greek and that obviously comes from a time that we still thought that dinosaurs were lizards and they are actually, for those that don’t know, considered reptiles because reptiles are not specific to a species or family. It has to do with how they look and how they act, so birds and not avian dinosaurs can also be considered reptiles along with lizards. It is a different kind of classification.
Sabrina: T. rex lived during the late Cretaceous period and they were among the last non-avian dinosaurs before the great extinction. They lived in western North America at the time it was an island continent called Laramidia, one of the largest known land predators.
Garret: They were 40 feet in length, 13 feet tall at the hips and they weighed about 6.8 metric tons. As Pete Larson mentioned in the interview a lot of scientists now think that it was a predator and a scavenger because if we look in modern animals you will see that the real big predators don’t necessarily have to hunt for their food, if something smaller kills it and they just want to go eat it and they can just come up and take it, which takes a lot of less energy than trying to go out and hunt for all your food. If you are big and scary you could just take from the little guys, so that is probably what T. rex did. It wouldn’t have made a lot of sense for him to do all that hunting by himself and you know I am saying he is mean.
Sabrina: T. rex is estimated to be capable of exerting one of the largest bite forces among all of the terrestrial animals. Scientists used to think T. rex walked upright and dragged its tail looking like a living tripod and in 1915, convinced that T. rex stood upright, Henry Fairfield Osborne, the former president of the America Museum of Natural History in New York, further reinforced this notion by unveiling the first complete Tyrannosaurus rex skeleton arranged walking upright. And it stood in its upright pose for 77 years until it was finally dismantled in 1992 and put in the correct position.
Garret: I always think of Barney and some of this others “cartoony” dinosaurs when they talk about how T. rex didn’t actually stand up right and you will still see depictions of the smart people that don’t understand dinosaurs with their upright position but when you take a closer look at the hips of T. rex you can tell that he was set up for walking with his body parallel to the ground which it was much more efficient. And on top of that the mass of length of T. rex, like we mentioned 40 feet in length, if it is standing upright the heart has to pump harder to get the blood up to its head and other thinks making it more difficult to stand up right. So, standing parallel to the ground is really the way to go.
Sabrina: So, in the Jurassic Park movies they got it right the way they depicted how T. rex stood with its tail of the ground but one thing that they got wrong was that the T. rex would definitely have been able to see you even if you stood still.
Garret: T. rex had a large part of its brain dedicated to vision and he had excellent binocular vision, both of its eyes face forward in front of its head. So, the notion that it used smell like it did in the movie to find people or could only see them if they were moving it is just for cinematic effect, really. T. rex shared the heightened sensory abilities of , heightened relative, rapid and coordinated eye and head movements as well as an enhanced ability to sense low frequency sounds that would allow a Tyrannosaurus to track prey movements from long distances.
Sabrina: They did have an enhanced sense of smell, it may have been comparable to the modern vultures which you send to track carcasses for scavenging. And research on the old factory bulbs show that Tyrannosaurus rex had the most highly developed sense of smell of 21 sampled non avian dinosaurs’ species.
Garret: One very interesting thing to me is how predators vs. herbivores would raise their young. There is a lot of evidence to show that herbivores kind of raised their young the way see turtles did, if you have ever seen those videos, where they go they lay a bunch of eggs and they kind of run away. I think that is severe but once they are hatched they are pretty much on their own. It is kind of a numbers game where you try to have as many kids as possible hoping that the species continues. So, Tyrannosaurus rex, there is a lot of evidence to show that they would raise just one young, teach them everything they knew about how to hunt and raise them from a young age up until they can hunt on their own. And they had to protect their young as well from herbivores and other animals that would see them as a threat and would want to kill them off. So, in a real weird way T. rex was a more nurturing parent than a lot of herbivores would have been at the time. So, going along with their nurturing, parenting behavior they also may have fought in packs or hunted in packs, obviously those kind of go hand in hand if you know how to raise your young and interact with other generations you might as well work together to make things easier for you on a hunt.
Sabrina: And T. rex probably also had feathers, at least on parts of its body.