One On One, Part II; No. 6; A Walking Tour of Dinosaurs in the Great Hall with Dr. Kevin Padian

This program is made possible by a grant from Sigma's Eye, the Scientific Research Society. I'm Faith Middleton and this is one-on-one. Everybody loves a good dinosaur story or movie, and that includes my guest, Kevin Padian, an assistant professor at the University of California, where he studies dinosaurs. Dr. Padian said something not long ago that I keep thinking about. He says there are thousands of dinosaurs living among us right now. So I called him up and explained that we want to know exactly what he means. He agreed to tell if we promised to meet him in Connecticut at the Peabody Museum, and that's just what we did. So this is it? This is it. This is the Peabody Museum of Natural History in New Haven, and it's a good place as any to talk about dinosaurs and other kinds of fossil animals, because actually the Peabody

has one of the world's largest collections, especially for a college museum of dinosaurs and fossil vertebrates. So what I think we'll do is I'll take you into one of my favorite places in the world, which is the Great Hall in the Peabody Museum. Okay, let's go. Will there be people in here? So you get a couple of people, the usual kids who, of course, can't be separated from dinosaurs, and they're crowded around the islands, looking at the large branosaurus and some of the triceratops and stegosaurus, and the other things that are in this hall, the hall itself. Here we are. Well, originally built. Yes, here it is. And so the middle island here is this great, a patosaurus, which is often called branosaurus, and with this long neck and weighs about any number of tons, depending on your perspective, and this stegosaurus in the back of it and campedosaurus is smaller herbivorous dinosaur. Now, as we're standing here, this dinosaur would be, how long would you say? Branosaurus, as it's often called, the correct name is a patosaurus, and if you look at it from the tip of its head to the end of its tail, it looks to be about 60 feet

long. And how many feet in the air? Well, it's funny. It depends, and it has a very long neck, and it depends on how you mount it. It's truly gargantuan, it's much bigger than any single elephant. It's probably about the size of five or six elephants high, and the neck could be stretched much higher, but it's limited by the ceiling. This whole building was built around the branosaurus, and you can see these very thick pig iron struts that are under scoring the entire skeleton. Well, at that time, of course, they didn't have the super light alloys that we have today, so they had to build it with this enormous pig iron, and a lot of this is the actual bone and plaster on display. And they had to build the whole museum here, which was constructed and opened around the early 20s, so that the walls downstairs would absorb the weight and take it out in all directions. Of course, today we do it entirely differently, but this is the whole thing about the branosaurus. It really is the museum's built around it. Now here is just a head sitting on a little stand. Yes.

The head was the head that occupied this skeleton for the better part. Well, since long before 1920, when the museum opened, so then they had the famous beheading and realized that they had had the wrong head on this dinosaur. Yes, a couple of years ago. Actually, Jack McIntosh realized that a long time ago, but a lot of people didn't pay any attention to him. In fact, it was even at the time when Marsh, O.C. Marsh, who is the founder of the Peabody Museum in a sense, his uncle, George Peabody, was the philanthropist who came up with a lot of the bucks to start the museum going, and the great collections. Well, Marsh found this partial skeleton, and he found the head a few miles away, and he put them together. But other scientists had found other specimens of the same animal, which Marsh called a branosaurus, which was correct names of dinosaurs by priority of name. It was named earlier, and so they eventually corrected it. It takes a long time, but we do things. What do you think these dinosaurs sounded like? Have the monster movies got it right? It's really hard to say. That's a very hard question to answer.

One of the hardest questions that paleontologists, I think, get asked is, what did they look like, and what do they say? What color were they? And what did they sound like? Well, we don't really know what they sounded like. Actually, Dave Weisshample did a study of what some dinosaurs might have sounded like. Not branosaurus, but some of the duck-billed dinosaurs that had big long crests on their heads, he determined by treating, you're going to think this is funny, but there's a lot of theories for why these things have big crests on their heads, and it could be because they wanted to smell better, or because they wanted to use it for a snorkel, but they can't, because the ends closed up, or because they used it as an air storage chamber, but it was only 2% of the lungs, so that probably wasn't it. What was this big crest on the head used for? Eventually, someone got the idea that it might have been, so they could make noise. Dave Weisshample tested this by building essentially a model of this as a resonance chamber and putting sound through it to see what the optimal sound waves were. He found out that, in fact, this particular crest of the dinosaur called parasoralophus,

the specimen, he worked on, had very good resonance frequencies that I think corresponded to an A-flat, a C, an E-flat, and I think F-sharp and maybe G-flat, which I think comes out to an A-flat 7th chord, and if you played it all at once, and so it's possible that these dinosaurs, when they had nothing better to do, would sit around tuning in each other, but one presumes that it was for defense to warn somebody that Tyrannosaurus was coming, or that something else was about to, or for keeping the whole herd together. We know more about herding behavior in dinosaurs, so that we do suspect from evidence as diverse as mass skeletons found together, mass footprints found together, and nests of dinosaurs that, in fact, mothering and herding parental care was quite possibly prevalent in many dinosaurs, which should not be surprising, because the only group of living dinosaurs has very advanced parental care, that is to say the birds.

Birds are dinosaur. It turns out that about 10 years ago, well, this is something that's been suspected for 100 years, but about 10 years ago, John Ostrom, here in the Peabody Museum, had made a very long detailed study of all the skeletons of Archaeopteryx, which is the first known bird from the upper Jurassic, about 135 million years old, and there are only about five skeletons in those couple of isolated feathers, but John Ostrom realized that these skeletons of Archaeopteryx were exactly like the skeletons of little carnivorous dinosaurs, except without the feathers, and this is sort of interesting, because in the subsequent 10 years, more and more evidence is accumulated that, in fact, there is no logical alternative to the fact that birds descended directly from these little dinosaurs in the, probably, in the later middle Jurassic, and that casts a very interesting light on things, because we have to accept that birds are dinosaurs, their members of the group dinosauria, as for example, we are members of the primates, members of the mammals, so, in a sense, birds

are feathered dinosaurs, just as we are hairless apes, see? And this is really, I mean, it's often, to me, it's the best news that people could have had in life, because, you know, everyone thinks dinosaurs are extinct, well, dinosaurs aren't extinct, most of them are, it's true, but most everything is extinct in groups that have lived since the Cambrian, and this kind of neat, because you think, well, dinosaurs are all dead, and it would have been great to see what they were like, but if you have birds today that are dinosaurs, you can learn a lot about what dinosaurs are, I mean, they're very numerous, they're very popular, they fly over the world, and, you know, people know them, they're real cute, two penguins, or, you know, dinosaurs are real cute. Is this frustrating to you, I'm getting the picture, that people think of this as archaic, it's long ago, they can't keep in contact, you want it to come alive again, don't you? It comes alive pretty readily, actually, people love dinosaurs, that's the, you can never get them away from that, they always want to know things that we can't tell them, because they want to know particulars about what color were they and what, you know, what do they sound like, but we don't know that so directly, we do know a lot about, for example, how many kinds there might have been around at a different particular time, we know

a good bit about their ecological diversity, we sort of know what they did for living, most dinosaurs, we can, we've gotten better on where they lived, dinosaurs, and a lot of dinosaurs, these great, big, long, hulking dinosaurs, for instance, historically we're always reconstructed as living in, in the water, in marshes and swamps and things like that, and that's kind of curious, because it's, it's, there hasn't been any direct evidence that their bodies were built to do that, as an example, you very often see these long neck, very heavy dinosaurs, underwater, with just their heads peeking out, and the typical story that you'll read in the kids' book is that branosaurus or a padosaurus, whoever it is, runs into the water to escape from the big, meat-eating dinosaur who's chasing it, okay, well this is all well and good, but the problem is, no, you can get them under the water, they're, first of all, their bodies, Bob Bakker did a very intense study of, of many features associated with these skeletons, and compare them to things like elephants and hippos, and they have a deep chest like elephants, they have, they have sort of hoof

like, as their, as their footprints show us, their feet were hoof like, like elephants, not like hippos, which, which keep their toes free because they need to maneuver in the, in the, in the muck there, and hippos have a very, you know, big sort of oval cross section of the body, not a deep chest like elephants, and, and these big sauropod dinosaurs tend to be like that, not like the hippos, besides that, if you get an animal in underwater so that only its head is peeking out, and all its neck is under, you know, you have about 20 feet of neck, and the lungs are 20 feet below the surface, well physics just says it's impossible to breathe, you know, it's like taking a soda straw and trying to breathe underwater, so anytime you see a picture of branosaurus or diplodocus or any of these animals with just their heads peeking out, well these are drowning, these animals, you know, see, you know, see that's the picture we always see of the Loch Ness monster. Oh yeah, well the Loch Ness monster is supposed to be a pleasiest sort, which also is a long neck, but it's not a dinosaur, it lived during the age of dinosaurs, and it's, I mean they, every evidence suggests that they went extinct about 65 or 70 million years ago,

so just with the other dinosaurs except for the birds, so it really isn't, it's, it's very difficult to understand how it could have survived in, in a freshwater lake for that long afterwards, because they're always found in marine sediments. You think it's not there? Well, it could be something, but it's probably not a pleasiest sort. But do we know in a paragraph about dinosaurs? We know that dinosaurs first appeared about 215 or 220 million years ago in the earliest part of the late Triassic, or maybe the Middle Triassic. The three periods in the Mesozoic era are the Triassic, the Jurassic, and the Cretaceous, and that encompasses the age of dinosaurs as we know it, a period of about 150 million years. The dinosaurs except for the birds died off at the end of the Cretaceous, and that's interesting thing too, because we often get the impression that there were all these

kinds of dinosaurs, and they began in the early time, and they all marched up to the end of the Cretaceous, and they died off, which is silly, because really at any one time there are anywhere between five and 20 or 25 different kinds of dinosaurs in a given rock formation in the Mesozoic era, but we, we don't, they keep replacing each other through time. They're not, they don't appear in a lump, and just, you know, march for 150 million years, and suddenly go blue-y, it's, it's not like that. So there were ones that walked around on, on all fours. There were some that stood up, and there were some that flew. Originally they, they started out on two legs. The first dinosaurs were fairly small, it seems like, and bipedal. They walked on their back legs. Part of being a dinosaur seems to have involved freeing the forelimbs, the hands, in fact, for locomotion, but we do know that their legs were perfectly capable of allowing them to run on their back legs, and their muscles in their tail helped to propel them and keep them up, and they were perfectly reasonable. Now, as they got larger and started, as some of them started to go back and eat vegetation,

they became sort of more cow-like and elephant-like, and they went back to four legs, because you got this big ponderous body that's always reaching towards the ground to eat plants, and it's just more comfortable on four legs, so that's what they seem to have done a lot of them. But the vicious, fighting dinosaurs that we see in all the movies. Well, yeah, the two-legged carnivorous ones, certainly, were right here in front of a skull of antardemus, often called allosaurus, from the Late Jurassic out in the west of the United States, and– Yes, it's from Como Bluff, Wyoming. One of the most famous dinosaur localities in the world, in fact, of Yale has one of the biggest collections anywhere from Como Bluff, which was a vicious one. Oh, yes, you can see its teeth are quite large and they're flattened on the side. They're sort of like daggers. This skull is about, oh, let's say, a foot and a half tall and about two and a half feet long when it's mouth is closed, and the teeth in it, well, you can see about two inches, but, of course, another two inches go inside the skull, and they don't have to get

you very hard to get a nice slice out of you. These were very predatory animals. These were not your average waffle or dinosaur. Can we stop for a second? Because I see a man who's obviously a superintendent in this building who's cleaning the glass case. Can we– let's ask him what his reaction is. Can we walk over for a minute? Excuse me. Do you spend much time here? We're doing just a little interview. Do you must spend much time walking– I think he's a famous man here. What are your thoughts when you spend time here? Do you find yourself thinking about what dinosaurs were like once? Oh, it always comes back to you. I'm glad I wasn't here when I were here at all. I wouldn't be here today, you know. What kinds of things do you hear from people when they're walking through? Well, I suppose to look, I get more out of the look, kids knew the grown-ups, they know all the names of the dinosaurs. They actually give the grown-ups education. The kids know the names of everything here, and the mothers and fathers act like, what's happening? You know what I mean? And the kids, they give them their parents' education.

Yeah. Good. Thanks. Okay. Thank you. We're talking with Dr. Kevin Padian, who's a professor of paleontology at Berkeley. Now, flying ones are your specialty. Yes. Yes. I deal with the origin of birds, and also with the pterosaurs, and the pterosaurs were the first flying vertebrates. Why is that the one that you want to spend time studying that? Well, I think they're very interesting. Actually, they aren't dinosaurs. pterosaurs are the closest group related to dinosaurs, but they are their own group. But we've recently learned that they are the closest things to dinosaurs that lived during the age of dinosaurs, and they have many features in common with dinosaurs. They really need animals, actually. One of the reasons why I've liked them is because they tell us something about a possible solution evolution can have to the problem of flight. If you want to fly, and if you're a vertebrate animal, a backbone animal with typical arms and legs and a head, our body plan, as opposed to the body plan, the starfish or

a clam. And you want to fly. You've got a limited number of ways to do it. You've got to make some kind of a wing, and you've got to make your body light. You've got to be able to solve the problems of being on the ground, as well as, or in the trees, as well as the problems of being in the air. And pterosaurs were the first group to a fall flight. They have all flight at the very beginning of the age of dinosaurs, more than 200 million years ago. Amazing when you see the size of them and imagine the weight of them. Well they started out quite small, only maybe a foot or two in wingspan. And some of the larger ones that existed towards the end of the cretaceous, that one there is about 16 feet in wingspan. But there were bigger ones up to about 25 in Teranodon. But then about 10 years ago, Doug Lawson, who was a student at Texas at the time, went out into the Big Bend National Park and came across some bones of a pterosaur that when reconstructed, have a wingspan of between 35 and 40 feet, which makes them half again as big as the largest living bird, like the albatross, or the giant condor, any extinct bird that

we know lived is about 25 feet in wingspan. This thing is 50% bigger. I mean it was enormous, and not only about it had a neck like a garden hose that had three enormous vertebrae in it that stretched the neck about, at least six feet. And the head was about four feet long or bigger. Many models of this animal have been made, the first one was on display at the Smithsonian in the Natural History Museum. And there are other models now being made for museums in New Mexico and San Francisco. I can't imagine how it flew. Well, very large birds and very large flying animals don't flap very much. They rely on winds and on thermals, which are sort of rising convection currents of warm air that come off the ground, that help them to soar all day. They soar. They don't really flap their wings. Flapping a wing that big takes an awful lot of energy, and you very rapidly lose your muscle physiology, really wear out quickly.

You know, I notice that while you're talking about this, you always keep it in the present tense as if they're still here. Yeah, maybe it's just that I'm in the past. I think that most of us paleontologists have our heads about, you know, firmly screwed on in the messes of look era, we're just, we don't recognize in some ways that the place to seem has come and gone, the ice ages, except of course, those of us who work on place to see in other kinds of fossils. We tend to think of these as living because they did live, and if they did live, well, then you can make all the assumptions about them. I mean, it happened, therefore it was possible, as people say. What do we get in the end if we know as much as we can about this period? That's a good question. We get, we get, I think, an appreciation of how the world could have been entirely different. A whole different ecosystem, dinosaurs were in a sense. The closest thing to dinosaurs today is the diversity of large mammals on the African plains, say, or in parts of Asia, where we see an ecosystem that supports large vertebrates.

None of them today, of course, are as large as your average dinosaurs from the messes ochre, but they are big, and they clearly must have been very influential on the ecosystem at the time. Consider, for example, elephants. Now, the African elephant has been very well studied by people in Kenya and other parts of Northern Africa who have to control the elephant populations as humans expand and take over their space. These are animals that need a tremendous amount of space because they wander constantly. They wander thousands of miles in a year in their little family groups and the males wander solitary. And they modify their ecosystem in very interesting ways. It's been learned, for example, that elephants like to take shoots from trees that are about an ancient diameter at breast height, and that's their favorite food. They eat some grass, they eat bark from trees. They eat lots of things, but if they eat too much grass, if they can't get the shoots that they want, they eat too much grass, they start getting diarrhea, which no one wants on the African plains, really, because an elephant puts through an awful lot of food in

a day, several hundred pounds. Now, if you consider how an elephant modifies its ecosystem, it takes its trunk and strips the bark off trees, which kills the cambium layer around the tree, so the tree dies. If it doesn't get what it wants to eat, but then you see new shoots spring up from the roots, and then it gets what it likes to eat. It runs around and essentially stops the trees from taking over in the African system. Now, if an elephant's, if elephants can do this today, I can scarcely believe that something as big as branosaurus or a patosaurus or diplodicus or any of those dinosaurs couldn't have had the same kinds of effects on their ecosystems, just the fact of processing, if an elephant processes several hundred pounds of food a day. What could one of these animals do in a day? And of course, spreading all that dinosaur manure through an ecosystem, plus trampling it with these 40-time hooves, you've got to have some kind of effect on an ecosystem. We know these animals were browsing in trees. We know, for example, that some of relatives of branosaurus or patosaurus like this were able to get up on their hind legs.

For example, prop themselves up with their tails and reach up into the highest branches with their necks, so we know they were feeding on vegetation that was both low and high, and therefore they clearly modified the ecosystems in very important ways. So this kind of discussion is still going on at conferences all over the world about dinosaurs. How many scientists study this? It's hard to say there are probably a couple hundred around the world, including students, people in museums, people who teach at universities, and people who don't have any set positions but who just are fascinated with them and do quite good research. What are the big issues right now? In dinosaurs, in the 1970s, the issue was mainly where they were blooded, and that was a very touchy. That debate went on for about 10 years, and there were all kinds of evidence that were reduced to try to demonstrate whether dinosaurs were worm-blooded or cold-blooded or what they did. There are really several problems here. It seems to me one is that whether the dinosaurs are worm-blooded or cold-blooded, which means relatively how high their body temperature was, and that's very difficult to tell

out of a dinosaur. We don't have a thermometer that we can stick into a dinosaur from that age. What I think people really wanted to know about when they were asked whether the dinosaurs were worm-blooded was about their behavior. They wanted to know, could they walk around all day, did they have to rest for most that they like lizards and crocodiles, or could they just wander, take a big kind of rist dinosaur, did it have to sleep under a tree for two weeks, or could it get up and prowl around actively for most or part of the day? Did it travel thousands of miles the way elephants do? Well, exactly, see, that's really interesting because that would have a tremendous effect on what we know about the possibility of dinosaurs migrating, and it turns out that it looks like dinosaurs were quite capable of migrating, that we don't have any seasonal records of whether they spent the winter in Florida or what, but we do know that we have found dinosaurs within what was then the Arctic Circle, so that if they spent in land of the midnight Sunday, couldn't have walked around the darkness for six months, they would probably want to come down where it was light for part of the time assuming they had to eat, so they

clearly must have migrated, and of course modern dinosaurs birds migrate all the time. So what's the big issue of the 80s? The new issue by the Alvarez group out at Berkeley, a group of geologists and physicists who decided that the reason the dinosaurs died out at the end of the Cretaceous is because a large asteroid came down and hit the earth and spread a dust cloud that covered up. The sun for a period of months or maybe a year, and temperatures either rose or dropped depending on which scenario is being put forth, and the plant life would have suffered. We know there was a lot of effect in the ocean life, and the dinosaurs and all the other animals consequently died out because either they didn't have any plant food or they stumbled around the dark and really couldn't get anything together for a crucial enough time that it led to their demise. Do you think the asteroid killed them? Well the best evidence from paleontologists who work on that seems to suggest that it didn't.

The plants, and a Leo Hickey, who's director of the Peabody here, has done a great deal of work on the plants all around the world at the end of the Cretaceous, and he doesn't find any pattern that would be explained by a large asteroid or comets or a series of comets hitting the earth and wrecking havoc. Bill Clemens, who works at Berkeley with me, has spent a decade with his students going out into Montana where the best remains from the end of the age of dinosaurs is, and he's looked at the changes across the Cretaceous and tertiary boundary that is from the very last days of the dinosaurs to the days following when they weren't there. And he sees, for example, different patterns of dinosaurs disappearing for millions of years before that in different environments, in different places geographically. And conversely, there are lots of animals that should have been equally affected by changes in temperature and light, such as crocodiles, alligators, turtles, frogs, lizards, who apparently weren't affected at all.

They just marched happily through. Is everybody out there waiting for a big find? Are people searching for a particular thing, a certain kind of dinosaur right now, that will answer all kinds of unanswered questions? Well, people are looking for living dinosaurs. I understand there's no... There was an expedition to Africa a couple of years ago by a couple people, one of biologists at Chicago and another one who was a mathematician who worked for well at the Jet Propulsion Laboratory in Pasadena. Do you mean the way they're looking for the Loch Ness monster? Yes, yes. These, in fact, they've made movies about this and so on. And I think the reaction of professional paleontologists in these expeditions is, well, gee, it would be great if they found it. But we just don't think it's probable. There's too much that would have to be explained in the last 65 million years. Why are there no other dinosaurs? Why did a small bit of dinosaurs only live or survive in the Congo or any part of the world or the Amazon or wherever people happen to look for them?

It would be neat, but why don't we know anything about it yet? We know the ecosystems of the world pretty well so far, and it would be surprising if we had nothing, no other evidence from that. That would be great. We'd all like to see that. We'd like to see a real dinosaur. Everyone likes to think about the lost world or one million years BC, everyone's favorite movies, I think, sort of revolve around the fantasy of going back in time. Although, as the maintenance man was saying just a minute ago, it'd be too scared, really. He's right, he's got a good perspective on it. I would be scared, witless, to go back there with a lot of those things around. Paleontologist Kevin Payden from the University of California, one-on-one is a production of Connecticut Public Radio. The series is made possible by a grant from Sigma's Eye, the Scientific Research Society. For a cassette copy of the conversation you just heard, call 203-527-0905, or this member station of the Public Radio Network.

The engineer of one-on-one is J. McDermott, Michelle Press and I co-produced the show. I'm Faith Middleton, thanks for listening.