Air Date: Week of November 17, 2000

Host Steve Curwood speaks with paleontologist Paul Sereno. He’s in the heart of Niger’s Tenere desert on a four month expedition to search for unknown dinosaurs.

Transcript

TOOMEY: It's Living on Earth. I'm Diane Toomey.

CURWOOD: And I'm Steve Curwood. Imagine the world about 100 million years ago, during the last great age of the dinosaur. During that time, known as the Cretaceous period, the world was breaking from one huge continent into two. Tyrannosaurus Rex, Triceratops, and Velociraptors, the most famous dinosaurs of that era, all come to mind. But those dinosaurs actually lived only in North America and Asia. So, scientists have recently turned to remote areas of Africa and South America to discover what other creatures shared that time on Earth. Paul Sereno is a paleontologist who's been digging and making new discoveries in some hard-to-reach spots during the past decade. Right now he's on a four-month expedition in Niger's Tenere Desert, 100 miles from the nearest oasis. We have reached him on his satellite phone. Hello, Dr. Sereno.

SERENO: Hi, how are you doing?

CURWOOD: What have you discovered so far this trip?

SERENO: Well, physically, we've actually excavated 15 tons of dinosaur bone. The bone is wrapped in plaster jackets, and inside those plaster jackets are new species that have never seen the light of day. There is, among other things, the first dog-sized dinosaur. We often think of dinosaurs as huge or only huge, but in fact small dinosaurs are some of the hardest to preserve. And we know of the raptors from North America. Well, we've never found anything from Africa of small size until now, so that's going to be a real exciting skeleton to clean off. We've got new predators of the larger variety. We've got long-necked dinosaurs that need to be named. And we have the world's largest crocodile.

CURWOOD: The world's largest crocodile. How big is big?

SERENO: The animal reached 40 feet or more. Jaws essentially as long as my body. This is a big crocodile, maybe twice the weight of the largest living crocodile today.

CURWOOD: Oh my. (Sereno laughs) Why is it that this particular part of the Sahara has so many dinosaur and crocodilian bones in it?

SERENO: You need two things to preserve fossil bone. I mean, the first is you need the right conditions at the time of death of the animal itself. So this was an area, literally, that was accumulating rock at a fast rate. So that when dinosaurs died and were swept by rivers, their skeletons were ultimately encased in rock, and this was then buried by subsequent rock. The second factor you need is really desertified, desert-like condition, so that there are no trees or grass or soil covering up that rock that preserves the bone.

CURWOOD: There have been several ages of dinosaurs, and the Cretaceous was the last great age of dinosaurs. And there's this big difference between the Southern Hemisphere and the Northern Hemisphere, you're finding. What are some of the important differences that you've noted, and why is it helpful to science?

SERENO: Well, we're really talking about the largest scale interaction of the Earth and its inhabitants. How did the break-apart of a continent, a super-continent, affect dinosaurs? We now understand that dinosaurs really started out, they looked much more similar worldwide in the beginning of the dinosaur era, in the Triassic Period. In the Cretaceous Period, we're learning from the finds we've made on this expedition and the ones previous, there really were a different set of dinosaurs here. Something took the place of Tyrannosaurs in North America. There were no Tyrannosaurs here, but there is another predator, called Carcardentosaurus, that reached the same enormous size but comes from a very different line of predators than Tyrannosaurus. And the plant-eaters were very different. If you came back and transported yourself back to the Cretaceous Period in Africa, you'd know the difference. You'd see Spinosaurss, fish-eating Tyrannosaur-sized animals that are very common in the beds that we are sitting in right now. There's nothing like that in North America at any time that we know of.

CURWOOD: You set up a Web site where students around the world or anybody can follow the expedition as you guys keep on working. What prompted you to do this?

SERENO: Well, my wife, an educator, Gabrielle Lyon and I began Project Exploration. It's an outreach, a science outreach group in Chicago. And we found that really the outdoor experience, a thought of the past, dinosaurs, all this can really engage kids and adults in thinking in a way that few other subjects can. And so, we've wrapped up these expeditions in Project Exploration in a Web site that I think is going to break some new ground for these kinds of things. You can go and find updates. You can find the background. You can find the interviews. You can find the special moments. It's really a great way to really set a huge audience on edge to see what we bring back and reconstruct.

CURWOOD: What will happen to these bones after you do all the necessary research back in Chicago? Will they go back to Niger?

SERENO: Well, these bones are going to go back to Niger. We may have some special relationship in the future, but we're concentrating now on preserving and building a real basis in Niger, not only for the population and the preservation of the bones, the population of the country here to realize the gems of their patrimony, but also for future visitors to the country.

CURWOOD: I'm thinking that many scientists would have a career before they discovered a new species or maybe two or three. Sounds like you're discovering them by the tens.

SERENO: We are making discoveries at a pace that would astound most who would look at paleontological exploration and understand that it is a very difficult thing. Part of the reason is that nobody has done it before, nobody's been here before in this kind of capacity. And you have to be passionate to do this. Daily temperatures, 125 degrees. We loaded fifteen tons of bone on a cool day, 115 degrees. We had to dig those fifteen tons of dinosaur bone out of solid rock in the desert with the sun and sand, and we don't even have personal tents. We sleep outside. These are the kinds of things that people will go and actually not only want to do but come back with the experience of a lifetime as part of an adventure. But it takes a special crew. It hasn't been done, and that's why we can make so many discoveries. Because they're out here to be made.

CURWOOD: Paul Sereno is a professor of paleontology at the University of Chicago. We reached him by satellite phone in the Tenere desert in Niger. To follow his latest African adventures and discoveries, go to www.loe.org. That's www.loe.org. Thank you, Professor Sereno.

SERENO: You're welcome.