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Profile: Mark Norell

Introduction to Dr. Mark Norell

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Dr. Mark Norell. ©AMNH

As one of the leading spokespersons for the current research connecting the origin of modern birds to a line of feathered theropods, Dr. Mark Norell and his groundbreaking discoveries have been featured on the front page of The New York Times on several occasions, most recently in May 2001. Mark is in constant demand for radio and television interviews and has appeared on NOVA Horizon, The Discovery Channel, and The History Channel. He has written two award-winning books, Discovering Dinosaurs and A Nest of Dinosaurs, and his work has appeared on the covers of Time and Newsweek, as well as the scientific journals Nature and Science.

As co-leader of the American Museum of Natural History's (AMNH) annual expeditions to Mongolia with Museum provost Mike Novacek, Mark has made some of the most important paleontological discoveries of the decade: the first fossil of a theropod embryo; the first dinosaur fossil brooding a nest of eggs; fossils of several new species with birdlike features; and the richest fossil-gathering locale in the world, Ukhaa Tolgod.

Mark's job as Curator and Division Chair in the Division of Paleontology at the AMNH provides the perfect outlet for his twin passions, science and extreme wilderness camping. His responsibilities range from wading through waist-high floodwaters in Mongolia to mingling with donors at black-tie fund raisers, requiring regular lifestyle transformations worthy of Clark Kent. Some might say a more apt comparison would be to a werewolf, as the shaggy man emerging from months in the desert would be almost unrecognizable to some of his colleagues back home.

" There are people who know me from the desert, and then there are people who know me here," Mark says from his office high in one of the Museum's stone turrets, which offers dazzling views of Central Park and the New York skyline. "I have my desert side, and then I have this side. And this side means getting dressed up a couple of times a week for meetings, dinners, cocktail parties, and openings."

Being a department head involves managing about 50 scientists and technicians, and typically requires answering 40 or 50 e-mails each night at home before going to bed. Still, Mark says, "I enjoy some aspects of administration. I'm still able to carry out my research because I have some really great people around me in my research group. And my graduate students are really fantastic. We're a pretty close, tight-knit group."

Leading one of the most active paleontology research team in the world has its advantages. "If something big happens, I can get one of my students on a plane to go there and see a specimen, and take pictures of it, take notes, and everything else, and then bring it back and share that with all of us."

Mark was born in Saint Paul, Minnesota, and his family moved to southern California when he was in second grade. As a child, he collected bugs, rocks, and fossils and made museum-style displays in his room, including the reassembled skeleton of a coyote. Mark's school offered the option to take science courses on weekends at the Los Angeles County Museum (LACM), an opportunity he jumped at. The museum scientists invited him to volunteer in the paleo lab, which he did for several years. "Then when I was in high school, they started asking me to go on expeditions," he recalls.

He joined several fossil-collecting trips to the Mojave Desert, as well as several closer to home. The Los Angeles area is rich in marine fossils, which are occasionally unearthed at construction sites. When this happens, the LACM is given an opportunity to do "salvage work," hurriedly removing fossils before they are destroyed. Mark says they retrieved some valuable fossils this way, including specimens of ancient whales and other marine mammals. Mark and another student at the LACM, Jim Clark, took trips into the desert on their own as soon as they got their driver's licenses. "We'd explore mountains and canyons, sleep wherever we felt like," Mark remembers.

Mark stayed in southern California to earn a bachelor's degree at Long Beach State and a master's at San Diego State, which allowed him to live most of the time in shorts and sandals and continue making treks into the desert. As an undergraduate, he made frequent trips to western Colorado to collect fossil dinosaurs, mammals, crocodiles, and lizards. In graduate school, he met a young professor named Mike Novacek. The two hit it off and co-wrote a paper, Mark's first published effort, for the journal Systematic Zoology titled Fossils, Phylogeny, and Taxonomic Rates of Evolution. Years later, Mike Novacek and Jim Clark remain two of Mark's closest collaborators. The three world-renowned paleontologists—Jim at George Washington University in Washington, D.C., and Mike at the AMNH, where he is now Senior Vice President and Provost—reunite each year for the AMNH's annual expeditions to Mongolia.

After earning his master's, Mark moved to New Haven, Connecticut, to pursue a Ph.D. at Yale University. One of Mark's ongoing contributions to paleontology has been to help drag the sometimes eccentric field into the computer age. The computerized methods he developed to analyze gaps in the evolutionary history of ancient species led him to Yale's molecular biology labs, because the same theories apply to the evolution of mutations in DNA. After his thesis, titled "A Cladistic Approach to Paleobiology and Evolution," won a prize at Yale, he accepted a post-doctoral position there to study evolutionary theory at the molecular level.

Though "the science was fantastic," the full-time position in a lab made him stir-crazy. "I missed going to the desert," he says. "I needed something else besides just going into the lab and sitting." Mark even considered quitting science. He recalls, "I was actually going to go to law school." What stopped him? "I got a job here," he says with a laugh.

In addition to administration and fieldwork, a big part of Mark's job is creating exhibitions. A major redesign of the AMNH fossil reptile halls in the 1990s gave curators in the Department of Vertebrate Paleontology the opportunity to reorganize the fossils in a way that traced the evolution of dinosaurs toward birds, which has been the focus of Mark's research at the Museum. The new layout simultaneously introduces visitors to cladistics by arranging the floor plan in a giant cladogram. "We wanted the halls to appeal to people on lots of different levels," Mark says. Visitors passing through quickly can simply admire the amazing fossils, while those who want a crash course in paleontology can read the fine print. Since new exhibitions are being created all the time in the Museum, Mark can regularly present his latest research to the public, such as in the recent Fighting Dinosaurs exhibition.

The least visible aspect of Mark's job is his theoretical research. Reconstructing the incredible diversity of life in the past from a tiny number of fossils inevitably requires a great deal of speculation. So Mark uses statistical techniques to remove some of the guesswork, or at least quantify the level of uncertainty.

"The fossil record is really, really bad," Mark explains. "People just don't realize how incomplete it is." For instance, while there are over 30,000 tetrapod (four-legged) species living today, the fossil record rarely contains evidence of more than 100 species from any given 10-million-year period, leaving thousands of others unaccounted for. By comparing different species that descended from a common ancestor, paleontologists can infer "ghost lineages" that link the known samples together. A good example is the connection between humans and chimpanzees. "A hundred years ago, you might have postulated that the human-chimp divergence happened, say, 10,000 years ago, or 100,000 years ago. Basically, you had no idea. We didn't have any fossils." However, since fossils of human ancestors have now been found going back 3.25-million years, "we can extend the line of chimps back in time to that 3.25 million year divergence, even though we don't have any fossils" on the chimp side. This "ghost lineage" of chimpanzee ancestors is an example of how cladistics can help fill in missing links in the fossil record.

Another problem in paleontology research is the poor quality of individual fossils. Researchers use checklists of traits, or "characters," to compare the bones of related species. Oftentimes, many of these characters cannot be observed because parts of the fossils are missing. A common approach is to assume that the missing parts fit the pattern created by the known parts. But this could lead to false conclusions. So Mark inserts random answers for the missing characters, then uses a computer to assess the probability of different outcomes. He has also experimented with giving different "weights" to characters that could be more significant. He lets a computer assign random weights to each character, then searches for patterns in the millions of possible results. These techniques introduce a greater degree of objectivity into a field that has relied in the past on subjective opinions.

Many of the Museum's historic fossil discoveries came from expeditions to Mongolia in the 1920s. But for most of the rest of the century, Mongolia was under the influence of the Soviet Union, which closed it off to Western scientists. The collapse of the Soviet Union enabled the Museum to resume its expeditions to the Gobi Desert in 1990. Mark arrived at the Museum just in time to take part in the first of these trips.

Their first expeditions were to sites that had already been visited by other scientists, and did not produce important finds. But in 1993, they discovered an exceptionally fertile site called Ukhaa Tolgod. "There were literally skeletons lying all over the place," Mark marvels. Best of all, instead of loosely strewn, squashed, or mangled bones, many skeletons at Ukhaa Tolgod were perfectly preserved, as if living animals had been suddenly turned to stone. In fact, this not so far from off from what actually did happen: Sudden collapses of giant sand dunes buried the animals alive, preserving them intact.

The sandy ground is so soft in Mongolia, and the wind so harsh, that enough earth erodes each year to expose a whole new round of fossils. Of course, the constantly blowing sand quickly destroys the fossils, too. So each year, the Museum crew revisits Ukhaa Tolgod to see what new fossils have emerged after 80 million years underground. Space and time constraints mean that for every specimen they take, hundreds of museum-quality fossils must be left to weather away.

An ordinary day at Ukhaa Tolgod can produce more discoveries than some of the greatest sites in North America produced in a hundred years. Primitive mammals from the mesozoic era-"the age of dinosaurs"-are especially precious to Mike Novacek, a mammal specialist. To put the value of Ukhaa Tolgod in context, it has provided 700 mammal skulls from the Mesozoic. The total number found in North America is less than ten. In fact, four-fifths of all the mesozoic mammals ever found have come from Ukhaa Tolgod. "It's a great locality," Mark says. "And every year we find more stuff."

Because the site is so small-about the size of a few city blocks-the Museum crew has plenty of time to prospect elsewhere during their Mongolia expeditions. They look in particular for exposed sections of the same layer of brilliant red rock found at Ukhaa Tolgod. There are few roads in the Gobi desert, so looking for new sites is trying. Trucks frequently overheat or get stuck in the sand. On one particularly bad day in 1998, progress halted 21 times, as the group's gasoline tanker repeatedly got stuck in the fine sand and needed a tow. They finally gave up and plunged off into the desert in a different direction, seeking solid ground.

But if the going were easier in Mongolia, the prospecting would not be as good. "If you're going to find really great stuff, you gotta go to places where nobody's ever been before," Mark explains. "And if nobody's ever been there before, there's usually a reason for it."
Going to one of the world's most remote places yields frequent doses of the unexpected. Some of these sights can be enchanting. On a 1996 expedition, their caravan encountered a vast herd of gazelles, numbering in the thousands. The gazelles raced alongside the trucks for a good half hour, dashing just inches in front of the speeding trucks. Other adventures can be enjoyed only in retrospect, as when they saw an immense sheet of white advancing down a hill towards them, which turned out to be a layer of hailstones bobbing on top of a surging flash flood. The freezing water quickly engulfed the road, covered their feet to their knees, and soon they were walking as fast as they could in deep, hail-strewn water-walking because they needed to test the depth of the puddles before risking the loss of their precious trucks. "That was pretty wild," Mark recalls fondly.

With no medical personnel, and a first aid kit that Mark jokes consists of "aspirin, tequila, and a gun," these expeditions are not for the faint of heart. But only rarely is anyone sent home early. For most emergencies, they can manage on their own. "I have a little first aid training," Mark says. "I can put in IVs, and stuff like that." He has been called upon to patch up a few wounds, but so far nothing more serious.

One task Mark has taken on personally is buying the food for the group. Though he believes in minimalist camping, this does not mean going without luxuries. As he told one interviewer, "My feeling has always been that when you're going camping, you should bring the basic 10 percent-an extra set of good outdoor clothes and foul-weather gear. And you should also bring the upper 10 percent: a few really great things that give you pleasure. In my case, really good food. If I carry these two categories of stuff, I don't even miss the other 80 percent." So while he eschews sleeping bags and tents (which he dismisses as "magnets for vermin") on most nights, through careful advance planning, he can quickly conjure up meals such as mushroom tortellini with chicken, tomato, and oregano sauce, or sushi rolls made from dried seaweed, a tube of wasabi, and vacuum-packed eel.

After a long stay in the Gobi, the transition back to life in New York is jarring. "When I get back from the desert, I can't even come in to work for a while. Sometimes I don't even come back to the country; I just stay in Beijing for a week or so after I get out. I have to get my act together," he says with a laugh. Often his wife meets him in Beijing and they tour China and Xinjiang, observing and collecting Asian art, a particular interest of Mark's. By then he is ready to settle in for another year of doing lab research and writing academic papers, as well as the steady stream of e-mails, meetings, and cocktail parties required to keep his department running smoothly and fully funded with grants for another year's travels.


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