DINO LAND PALEONTOLOGY INTERVIEWS
Thirty five years ago dinosaurs were portrayed as lumbering, dumb beats waiting to go extinct. Then, in a flash of brilliance, a group of men redefined this image. Led by Dr. Robert Bakker, this new group rewrote the conventional wisdom on dinosaurs. Suddenly they were quick, smart, agile creatures who had a reason for dominating the earth for such a long period of time. During this dinosaur Renaissance Bakker, John Ostrom, Armand de Ricqules, and others raised questions on the ancestry and metabolism of these redefined dinosaurs. Ostrom, and his brilliant Yale student Bakker, led the charge that resulted in the now nearly universally accepted idea that birds evolved from dinosaurs, and the still hotly debated idea that some dinosaurs may have been warmblooded. While it is still debated just who first proposed this heavily debated idea of dinosaur endothermy, Bakker seems to think that he did, pointing to a paper on the issue that first appeared in 1968. Still others point to Ostrom, but one thing is certain. Robert Bakker will always be noted, and quoted, on this hypothesis.
While the endothermy idea has brought Bakker fame, he has also spent decades conducting countless field expeditions that have resulted in numerous new species. In addition to this find, he has described Nanotyrannus, worked on the nesting habits of carnivores in Wyoming, has tried to put the Jurassic in context, described the Jurassic-Cretaceous boundary, and has proposed one of the most controversial extinction causes. Currently he is attempting to recreate the sound a Brontosaur made (note-he uses the genus Brontosaurus).
Last April I had the chance to interview Bakker from his Colorado office for my book project. While I asked him some of the basic extinction and endothermy questions, he also gave me new insight into the world he loves best-the Jurassic. Here are some highlights:
S.B: I once read that you caught the dinosaur bug after reading a magazine as a child. Is this correct?
R.B: Yes. When I was ten years old, in the fourth grade, I read the famous December 7, 1953 Life Magazine. To me it was the most famous single magazine on dinosaurs ever written. The article, done by Lincoln Barnett, was very well illustrated and showed dinosaurs as part of the living history. I also got a chance to go to the American Museum in New York, which helped my interest.
S.B: Why did you decide to take this interest you caught from a magazine and turn it into a career? R.B: The impact of the magazine was very strong. As I said, it portrayed dinosaurs as part of the geological history, part of the story of life on earth. It struck that paleontology was the career for me.
S.B: I have seen many different affiliations next to your name. What have been some of these jobs you have held?
R.B: As an undergraduate I held many small jobs as an illustrator. Also, while I was at Yale, I had a job teaching kids at the museum. At Harvard I was in charge of the comparative anatomy labs. After that I left for Johns Hopkins University in Baltimore, where I taught anatomy to pre-med students. I left that job in 1982. Since then I have held many jobs at museums in Colorado and Wyoming. I have also taught summer courses at the University of Colorado.
S.B: What about the Tate Museum of Casper College in Wyoming? You list them as your affiliation in Raptor Red.
R.B: I am an adjunct curator there. One of my major goals is to develop a web of the small Wyoming museums and create a major museum system. There are about eight of these museums, and they are all scattered.
S.B: You have done a great deal of work on the Jurassic period. Where have you done this work? What are your goals?
R.B: I have been working every summer since 1974 at Como Bluff to try to put the Jurassic into context. When you see a paining depicting the Jurassic you see all of the dinosaurs together. Diplodocus shares a home with Stegosaurus, etc. I dig not to get great specimens, but to sample every possible habitation, from dry soil to swamps to lakes.
S.B: So, what can you tell me about the Jurassic? Who lived where?
R.B: We have found some totally aquatic dinosaurs, dinosaurs that preferred wet habitats, and others that only lived in trees. Stegosaurus was common only on well drained, dry soil. I can tell you that Brontosaurus and Camarasaurus were everywhere.
S.B: You have also done a great deal of work on the Jurassic-Cretaceous boundary. What do you see happening here?
R.B: We see a huge extinction of dinosaurs, not total, but we lose most of the animals that had been common. This occurred when crocodiles and turtles diversified. It follows the same pattern at the end of the Cretaceous, when extinction hits big animals and the littler guys diversify. I went to South Africa to study the late Permian and Triassic and it followed the same pattern.
S.B: You have also made some very interesting field finds. Among these was Epanterias. What can you tell me about this find? It is a member of the Allosaur family, correct?
R.B: Epanterias was the last member of the Allosaur group in North America. Its skull is similar to Allosaurus, but its legs are thicker. It is longer, but lower than T. rex, and has smaller teeth. It is only found in the last slice of the Jurassic, and proves one of Cope’s greatest theories. He said that animals get bigger and bigger and die out. This is the last Allosaur and it is was the largest.
S.B: What other interesting field finds have you made?
R.B: I discovered the very first raptor in the Camarasaurus quarry. I also discovered the only complete Brontosaurus skull.
S.B: Okay, now it is time to get to the endothermy question. Did you propose this first, or was it Ostrom?
R.B: First of all, we have to remember that in 1836 Edward Hitchcock studied dinosaur footprints in Massachusetts and thought that they were made by hawks that ran. This was very accurate for 1836, dinosaurs compared to hot blooded birds. In 1941 Richard Owen said that the dinosaurs were almost hot blooded. My first paper on the issue was published in 1968 and it was on the history of the idea. If you follow the history of mammals and dinosaurs, you come to see some striking things. In the Permian and Triassic the mammal like reptiles were very close metabolically to true mammals. They were hot blooded. When the first true mammals came along they were very small. This seems odd to me that a group of creatures so advanced would go from large to tiny during the time when the dinosaurs were large mammals, unless the dinosaurs were also advanced-being hot blooded. If the dinosaurs were cold blooded this would not make sense. To me it seems that the warm blooded dinosaurs replaced advanced mammal ancestors that were warm blooded, also.
S.B: If this is true, how can we prove it?
R.B: We can look at the growth of dinosaur bones, like de Ricqules is doing. We can also look at the respiratory system. Many dinosaurs had hollow like backbones that included air chambers leading to the lungs, like birds (who are hot blooded). Owen also discussed this (hollowed out bones) in the 1860’s.
S.B: I also understand that you are working on the nesting habits of carnivorous dinosaurs.
R.B: Yes. I am working on the nesting habits of meat eaters in Wyoming. There are several spots where Allosaurs dragged prey to feed their young. You can find broken teeth of babies and adults when eating on something large. When looking at the evidence of feeding on large prey, you can see every size tooth from hatchling to adult in one spot. The babies may have been fed in the nest until they were full grown, like in eagles and hawks.
S.B: What about extinction, you point to disease?
R.B: It was not an asteroid or comet, because it would have killed everything. I do point to disease. When big animals are spreading and mixing extinction occur. You can see this with elephants. One researcher just determined that African and Indian elephants make each other sick. When a new animal or plant is introduced to a habitat bad things happen. The biggest danger to native wildlife is foreign wildlife.
S.B: If so, how could we prove this?
R.B: There is a record of land bridges forming, and animals spreading. There, of course, is a record of extinction. Look at snails. They don’t spread very fast, and they do not become extinct. Land bridges were everywhere during the extinction, many species were spreading, and there were many diseases.
S.B: If this is so, then why did such a large percentage of sea life become extinct?
R.B: Often extinctions in the ocean occur at the same time as those on land. Then again, the ice age extinctions lost many big animals, but not many sea faring ones. At the end of the Cretaceous, though, oceans were changing and this was non related to the land extinctions caused by disease.
S.B: What projects are you currently partaking in?
R.B: I am trying to recreate the sound that Brontosaurus made. I believe that their heads vibrated because several of the bones around the eyes are loosely hinged (these are usually tightly bound in other species). When it sneezed its whole eye socket would rattle.
S.B: Last, what do you think about Ostrom and dinosaur-bird evolution?
R.B: Birds evolved from a small raptor like theropod. Feathers predate birds. There are some early Jurassic footprints of dinosaurs sitting down with feather like impressions by their feet. These were discovered in 1838, but restudied two years ago.
S.B: One more thing, will you be appearing at the Burpee Museum of Rockford, Illinois’ out of the Rock Paleo Festival next February? Early rumors show that you may be one of the keynote speakers?
R.B: Hmmm…I haven’t gotten anything on it yet, but if I do it will be a possibility.
S.B: Well, that is it. Thank you for your time, Dr. Bakker.
R.B: Thank you, Steve.
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