Paleontologist Mark Norell, who found the first fossil of an embryo of the family of dinosaurs that includes Tyrannosaurus rex, made critical discoveries linking birds and dinosaurs – and was once dubbed “the Coolest Dude Alive” by The Wall Street Journal – is coming to Raleigh on Thursday to give a talk at the N.C. Museum of Natural Sciences, where a special exhibition that he curated, “The World’s Largest Dinosaurs,” is on display.
Among other things, Norell will discuss technology that has allowed his research team to determine the color of the feathers on some dinosaurs and help them begin to explore the color of dinosaur skin. He’ll also sign his book “Barnum Brown: The Man Who Discovered Tyrannosaurus rex.”
We caught him between digs in far-flung places like the Gobi desert. He was in New York, where he heads the paleontology division at the American Museum of Natural History. We asked him about his work, the state of paleontology and about some of the latest scientific thought on dinosaurs.
Q: Mark, your degrees are all in zoology and biology. Is biology the field that produces paleontologists these days?
A: Primarily they do come from biology. The field has become much more biological and less geological.
Q: My sense is that paleontology started with people who weren’t particularly knowledgeable about science, and then like a lot of fields – say, archaeology – it steadily grew more sophisticated, then made a sudden great leap recently because of the explosion in the power of computers, the rise of big data and other advances in technology. Is that accurate?
A: Well, yes and no. Paleontology has really been able to take advantage of some pretty cutting-edge stuff through the years, even going back to when scientists were first X-raying stuff at the turn of the century. We have some great instruments, like CAT scanners mass spectrometers, some incredibly precise and very, very expensive machines. Paleontology has always been, because no university in the United States gives a degree in it, a very multidisciplinary kind of field where people come at it from the geological perspective.
There are people who look at sedimentology and geochronology and that kind of thing, and then there are people like myself, who are basically biologists who work on fossils some of the time. So it’s a bit different from archaeology in that sort of way. Most archaeologists, quite frankly, aren’t scientists. They come out of liberal arts backgrounds and in my opinion it has hindered the field a little bit because they don’t have the kind of rigorous training in mathematics and things like that that give you a lot of power when you’re trying to answer questions.
Q: But still, I’m guessing that the computer revolution has driven some findings. How much of what we know about dinosaurs, the good data, has emerged in recent years, with the computer-driven acceleration in technology and methods of inquiry?
A: Certainly now that we have faster and faster computers doing imaging and rendering and tomography, that whole visualization aspect has been helped a lot. And also just having faster computers. A series of problems I worked on a long time when I was in grad school and I just couldn’t do, I’m pulling the files out of my cabinet now every once in awhile and my students are working on them. Now, you can just do some of these things by brute force. ... You can do a simulation and do the experiment a couple of billion times, then you’ll have a distribution to be able to test against.
Q: It seems like we have just a tiny fraction of the data about dinosaurs. There is a lot of missing data.
A: Not only is the data missing, the data is just biased. Even if you’re trying to look at the number of species alive in any given time period. It’s not like you have removed 90 percent, or even 95 percent, of them. You’ve removed over 95 percent of them, and it’s very selective. Different environments, for instance, have biases against small things being preserved or large things being preserved. So we have an overabundance, even of fossil vertebrates, of things that lived in water and ponds. The turtle fossil record is pretty good, but the record of things that lived on land is not so good.
And if you look at things that are fossilizing today ... you can go out to some place like the Great Plains and see skeletons of bison which have been laying out 100 years or so that are quickly buried and are in the riverbanks, and those are fossils in the making. You don’t see that kind of thing when you go to either high-energy, high-altitude environments like the Rockies, or you go to the places that have the highest biodiversity on the planet, like the Amazon Basin. And I’ve seen this – in the morning I see an animal that has died and dropped to the ground and I come back in the afternoon and it’s all the way down to the grass, because it has been scavenged. So we don’t have a sample of animals that lived in those kinds of environments.
Q: So you’re saying we don’t know anything about more than 95 percent of the species of any of those eras?
A: I would go further than that. I’d say 99.99 percent of the species are missing. If you look at it from the perspective of today, the major back-boned animal groups alive today, there are about 5,000 mammals, about 10,000 birds, a few hundred turtles and you’re looking at about 20,000 species total that are alive on the planet with us right now.
If you go back in time, just pick a random number, say, 5 million years ago. And you look over a 1 million-year period, you’re only going to come up with a couple hundred animals, at the most, that we have fossils of. And if you think about everything that went extinct over the last several ice ages, those 20,000 animals today would probably be about 100,000. So the record we have isn’t very large at all.
Q: You’ve done a lot of work on feathers. What was the point of feathers on dinosaurs?
A: I think we can make a pretty good case now that feathers are primitive for dinosaurs, so the ancestral dinosaur was feathered. It was probably just like I am right now – on a cold day in New York I have my down coat on. It was probably to keep warm.
The most primitive feathers are what we call stage one feathers, and they’re really just like long filaments, kind of like hair. But instead of hair like we have, that’s solid, these were tubular structures, like the main shaft of a feather, but really fine and really small.
Then, I think that we can make a good case next that feathers were used for display, because we see a lot of animals that weren’t flighted but have these fantails and feathers in the top of their heads and other parts of their bodies.
And only after that were they co-opted as part of the flight mechanism to help animals fly. That’s pretty much the story of evolution, some existing structure is co-opted for something else.
Q: But not all dinosaurs were feathered, though?
A: Well, I think there’s a good chance that all dinosaurs would have been feathered at some point in their life. We don’t know that for sure, that’s speculation, but at the same time I think we have very powerful evidence now to say that the ancestor of all dinosaurs had feathers. From that you would predict it, and we have other evidence. For example, we have some specimens that show feathers and scales in the same animals.
It’s kind of analogous to the observation about hair and mammals. We have absolutely no direct evidence that australopithecines or Homo erectus had hair. But chimps and we have hair, and they are more culturally related to us than chimps, and so we assume they have hair.
Q: What are some of the most persistent misconceptions about dinosaurs?
A: Well, that dinosaurs are extinct. And they’re not. Birds are alive today. And just like humans are a kind of primate, birds are a kind of dinosaur.
Another is that all dinosaurs are big. That’s certainly not the case. Some dinosaurs were the largest terrestrial animals ever to live, but that’s kind of an exception. There were tons of small ones as well, and a lot of that misconception comes from the early history of dinosaur collecting where people were just trying to get the biggest specimens they could from the American west and put them on display in museums. You can find small ones, but the tiniest ones tend to be uncommon because they don’t make a good fossil like the big ones do. Of the extinct dinosaurs, we do know of one about the size of a finch, for example.
If you look at the history of it, some of the great collections in the United States, it was a competition among millionaires to see who would have the largest. In other cases it was purely showmanship. The famous American paleontologist O.C. Marsh at Yale, one of his best friends was P.T. Barnum.
Q: What are you working on now?
A: We have a lot going on. We have excavation projects ongoing in Eastern Europe and China and Mongolia. And we have a big project looking at the evolution of brains in dinosaurs, using CAT scan information to be able to build virtual brains for all these different animals. And because of other studies we’re doing, we know in living birds what various parts of the brain do.
I had this idea, 15 or 20 years ago, that the brains of these animals reorganized when they started to fly. Because if you look at the brains of birds today they’re quite different from the brains of their closest living relative, crocodiles. And bats, their brains are quite a bit different from those of other mammals. I wasn’t able to answer it in the old days because we didn’t have the appropriate technology, and we didn’t have the appropriate specimens.
But we had recovered a lot of the important specimens in Mongolia over the past two decades, and we have the CAT scanning now. And it turns out that I was completely wrong. The brain of oviraptors and velociraptor and things like that, it turns out, are identical to those of very primitive birds. So, by the time birds were starting to fly they already had what we would call a flight-ready brain. Now we’re following that up more by adding other kinds of dinosaurs and experimenting on the brains of living birds to come up with a picture of what different parts of the brain are doing.
Q: What are the rewards of this work? I mean, you’re not going to pull down investment-banker paychecks in the paleontology racket.
A: One of the things about being a paleontologist that’s incredibly rewarding is that it allows you to be able to subliminally teach a lot of things to the general public. When you have an exhibition, people are interested in dinosaurs and they come and see it and you can talk about everything from evolution to earth history to biomechanics and expose people to all these things that are really important from a science literacy perspective because they transcend a lot of different sciences beyond paleontology.
Considering the state of science education in this country, any time you have the opportunity where people appreciatively come in, seek something out to see it, it’s a great opportunity.