The world’s most famous dinosaur hunter is back on the rampage. While working on the implementation of interesting projects to bring science closer to young people, Paul Sereno is preparing a new expedition to Africa, where he hopes to find data that will help him to reconstruct the family tree of dinosaurs, their ancestors and their descendants.
–It’s hard to believe that birds are descended from dinosaurs. Do scientists currently have enough evidence to prove it?
-More than a hundred years ago this theory was formulated for the first time. Darwin himself found similarities between the bones of birds and the fossils of dinosaurs, beings very little known at that time. We currently have a lot of evidence that allows us to understand how the transition occurred. For example, we have found fossils of dinosaurs that had feathers and of birds so primitive that it is difficult to know if they are birds or dinosaurs.
–How did the birds evolve? Why did the feathers appear if they were not useful for flying?
-Many animals have organs that have survived evolution for reasons other than their current function. Maybe humans were not designed in principle to walk upright and that is why we have problems with the spine. It is very likely that the feathers were originally used to cover the bodies of small dinosaurs, to maintain temperature. In Spain there are fossils of small dinosaurs, with very strong feathers and upper limbs. These animals developed a new lifestyle and ended up having the ability to fly.
–What does the discovery in China of a fossil of a Microraptor, endowed with four wings, indicate?
-It’s fabulous. It gives us an excellent idea of how the ability to fly could have developed. The Microraptor is one of the smallest dinosaurs known. It is clear that these types of animals could jump from one tree to another and glide with the help of their feathered wings. From this ability, thinking about the appearance of flying birds is much easier.
–Why did the dinosaurs disappear and the birds survive?
-The extinction that occurred at the end of the Cretaceous, 65 million years ago, especially affected large land animals because they were relatively few and had little chance of finding shelter and food. It is true that the birds did not have much chance of escaping a catastrophe such as that caused by the impact of a meteorite, because if food was lacking, they could not survive for many days, as crocodiles do. But the nucleus of the cataclysm was in Central America, where the birds surely found some refuge on the continent or on an island.
–Can we go back and recreate the dinosaurs?
-There is no dinosaur DNA that allows us to make stories like the one in Jurassic Park a reality, but we can go a long way by discovering new fossils and reconstructing the evolutionary tree of these exceptional creatures.
–How did your career begin in the discovery of the origins of dinosaurs?
-In the middle of the 20th century, some interesting fossils were found in Argentine Patagonia, including the hind leg of a large dinosaur, which fell into oblivion for three decades. So when I was able to create a research team at the University of Chicago in 1988, we decided to go do field research. We were young, we did not know the area, we did not speak Spanish and the local scientists told us that we would not find anything, but in three weeks of excavations we discovered the first skeleton in good condition. That changed my career. I realized that, by persisting in the effort, we would find more interesting things. We unearthed a good specimen of Herrerasaurus, a fairly primitive carnivorous dinosaur, about 4 meters high, and about 300 fossils of other species.
–You must keep very good memories of Argentina …
-Yes, in 1991 we returned to the same area and discovered the remains of a small Eoraptor, which lived about 228 million years ago. It is one of the oldest known dinosaur species.
–How did some of these species, which evolved from small reptiles, become the largest land animals that have ever existed?
-They probably had a very different physiology from mammals, most likely they were halfway between cold-blooded and warm-blooded animals. The great dinosaurs had their own system to avoid the loss of heat and energy.
–How did the drift of the continents influence their distribution on Earth?
-I have been researching on the subject for ten years; in fact, I work a lot in Africa because it’s one of the missing pieces in the dinosaur evolution puzzle. Until 50 years ago, 90 percent of the fossils had been found in Europe, North America, or Asia. Nobody had realized that the largest desert in Africa and the world, the Sahara, is full of rocks from the time of the dinosaurs. We can recreate the Cretaceous world in Africa.
–Did you dream of “hunting” prehistoric animals as a child?
-I was a bad student and I thought I was an artist, because I had some talent for painting, but I am also an adventurer. I couldn’t imagine a life without traveling; I dreamed of participating in all kinds of expeditions until one day, when I had already started my Fine Arts degree, I was lucky enough to visit the Museum of Natural History in New York. In those rooms I discovered that science was not necessarily a cold, boring discipline full of people in white coats, and then I knew what I wanted to do with my life. I understood that scientific activity would allow me to combine adventure with artistic qualities, although the dinosaurs came later.
–Because when you were young, there was no “dynomania” …
-It is true, although I was not interested in studying dinosaurs when I was a child. Well, the truth is that he was not interested in any kind of studies. Perhaps that is why it is so important to me now that young people have incentives to be interested in science. Adventure is a way of attracting them to studies and research.
–After his visit to the Museum, he began to study Biology. How did you channel your specialization?
-When I finished the first part of my university studies in Chicago, I proposed seven topics for my thesis, from the origin of whales to the evolution of ungulates. I finally discovered that I was attracted to dinosaurs, perhaps because they had never been treated seriously.
–And he found his first fossil …
-My first important find was in Argentina in 1988. We were exploring a large area of 150 square kilometers, which we traveled from end to end without any result, and we were going to give up. But before moving the camp to another location we had a day off, and I decided to dedicate it to scouring the area again with some volunteers. In the exact place where I left the backpack, we found the fossil of a huge Herrerasaurus. It was such a glorious moment that I didn’t dare look again for fear it would disappear. I started crying with joy.
–What is the most important fossil of your career?
-I suppose that the oldest dinosaurs can be considered the most important, perhaps those found in Africa …
–It was precisely in the Sahara that you and your team of paleontologists made a spectacular discovery: a large reptile, which you unveiled in 2001 …
-Yes, the Sarcosuchus imperator, a giant crocodile of more than 13 meters in length that lived in what is now the desert 110 million years ago. It was an amazing animal that ate dinosaurs. We were also able to offer a very approximate image of what it was like thanks to the artistic recreation made from the fossils of three different specimens.
–Do you know other scientists criticize you for your popularity?
-Popularity is a double-edged sword. I am an unusual case: a popular scientist at a prestigious university. For this double reason I am more obliged than anyone to base my work on scientific articles and to show that they have a solid foundation. Regarding criticism, you have to know how to accept it; there are worse things in life.
Joaquim Elcacho
This interview was published in May 2003, in number 264 of VERY Interesting.
