What Were We Searching For and How Did We Decide Where to Look

The most common components of dinosaur research are the discovery of previously unknown species and the analysis of their diversity and evolutionary history. Other important biological components are the study of how dinosaurs changed through time, as well as how they moved and behaved. These intriguing scientific investigations, however, must be founded on a clear understanding of the genealogical relationships of each species. Without knowing the origin of each group, which represents the starting point for later physical transformations, it is impossible to reconstruct how a new anatomical structure or behavior came to be. Related geological research involves estimating the age of the rocks that contain dinosaur fossils and determining what the rocks can tell us about the climates and environments in which the dinosaurs lived.

Fossilization is a natural geologic phenomenon, and fossils are found worldwide. But to discover new dinosaur species, a paleontologist can't just fly to some far-off part of the globe and start digging, because the chances of finding previously undiscovered species are quite low. In fact, paleontologists usually find new species in a previously unexplored place where rocks of the right age are exposed. Consequently, dinosaur expeditions are preceded by a careful examination of several possible areas for exploration, with the final decision based on the goals of an underlying research program as well as an assessment of the accessibility and risks of the selected areas.

Every year, international expeditions scout some of the most inhospitable regions of the world for dinosaur bones, from the deserts of northern Africa and central Asia to the frozen peaks of Antarctica and Alaska. Numerous smaller expeditions are conducted in almost every country. In our case, we knew that Patagonia had produced an incredible assortment of dinosaur fossils over the previous century. The scientific reports describing those dinosaurs also contained information about where they were found, the kinds of rocks entombing them, and their approximate age. In addition, we knew where our colleagues were conducting explorations and finding new kinds of dinosaurs throughout the region.

Yet in spite of all the earlier and contemporary fossil discoveries, most parts of Patagonia are still virtually unexplored by paleontologists, partly because of the region's size and partly because of its desolate landscapes. Most modern inhabitants of Patagonia live in small towns scattered over large stretches of sparsely populated desert. Aside from the highways that connect these widely separated towns, roads are rare and unpaved. Oil companies built most of these dirt roads to facilitate their search for oil and natural gas. In the wake of these geological prospectors followed smaller field crews of paleontologists prospecting for fossils. But fossil exploration in Patagonia today is similar to paleontologic exploration in the American West at the turn of the century, when famous dinosaurs such as Tyrannosaurus and Diplodocus were first discovered.

One of these unexplored regions is near the center of the province of Neuquen, some six hundred miles southwest of Buenos Aires as the crow flies. There, vast badlands formed from rock layers deposited near the end of the Mesozoic era are exposed around an extinct volcano called Auca Mahuida. We knew that superb fossils of ancient birds and their closely related dinosaurian cousins had been found in comparable rock layers not far from this area because Luis had studied them while compiling his dissertation on ancient Mesozoic birds from South America. Over the last few years, the origin and early evolution of birds has become one of the most active areas of research in vertebrate paleontology. Yet, except at a few unusual sites, remains of these ancient birds are extremely rare, and as such, they represent highly prized discoveries for paleontologists.

So, in 1996, Luis and some members of our field crew undertook a brief exploration of the rock layers exposed around Auca Mahuida at the end of a field season to central Argentina. The goal of our initial expedition was not to find skeletons or eggs of large dinosaurs, but rather to search for the delicate fossil bones of the birds and their dinosaurian relatives that inhabited Patagonia near the end of the Mesozoic. Instead, Luis and his crew discovered some fossil bones of giant, plant-eating sauropods, as well as fragmentary remains of other dinosaurs and creatures that had lived with them. Even though no fossil birds were found, the rocks of this region looked promising and deserved more of our attention. This short foray into the region around Auca Mahuida proved crucial to our later success in that we gathered important information about the rocks of the area and identified where we could find water, food, and shelter. We also began to familiarize ourselves with the roads and tracks that might allow us to gain access to promising outcrops.

After returning from the 1996 trip, we decided to organize another expedition in 1997. This field trip would include a more extensive, monthlong exploration of the Auca Mahuida area with a larger crew. Our initial goal was the same as that of the previous year: to find the remains of ancient birds and the small, meat-eating theropod dinosaurs that are closely related to them. But even if we didn't find any birds, we knew that a more complete collection of the ancient animals from this region, as well as a thorough study of its rocks, could enhance our understanding of the age of these birds and the ecosystem they had inhabited.

As with all expeditions, numerous challenges faced us before we could embark. We had to draw up detailed plans and make agreements with the governments and paleontologic institutions in the areas where we hoped to work. We also needed to find funding for tents and other camping gear, cooking equipment, food, drinks, collecting tools and materials, renting and maintaining vehicles, and airline tickets.

Suzi Zetkus and Luis took charge of flight arrangements, buying supplies, and renting our vehicles. This was an enormous job. Suzi volunteers countless hours of her leisure time to tour visitors at the American Museum of Natural History. In addition, she has participated in several paleontological expeditions both for the museum in New York and for other institutions. She served expertly as our expedition coordinator as well as an indefatigable driver, keeping track of supplies and running errands between our camp and Neuquen, the nearest large city. Detailed lists of the supplies we would need had to be compiled and each item obtained. Some items were purchased in Argentina, but others had to be bought in New York and shipped to Buenos Aires on our flights.

Our camping and cooking equipment was fairly standard. But for celebratory asados, a special kind of barbecue commonly practiced by the Argentines, we packed a grill and a couple of iron rods to build a cross on which to hang the carcass of a sheep or goat over the fire.

Our list of collecting equipment was more specialized. To excavate fossils and rock samples, we shipped shovels, picks, rock hammers, crowbars, chisels, brushes, special glue, dental tools, and sample bags. To construct protective jackets around fossils, we bought large bags of plaster, plaster bandages, burlap, and dozens of rolls of toilet tissue. We had to accurately record the location of our fossil sites and places where we collected rock samples, so we ordered geologic maps and GPS (global positioning system) units. These small computers receive signals from orbiting satellites for calculating the precise longitude and latitude of the place where one is standing. A special instrument called a Brunton compass was required to measure the thickness of the rock layers that formed the ridges from which we collected samples for magnetic analysis. These samples had to be wrapped in aluminum foil and secured with masking tape for the trip back to the lab.

In developing the collecting agreements with the local governments and institutions in Neuquen, we received invaluable assistance from our colleague and co-leader Rodolfo Coria. Luis and Rodolfo had become friends when Rodolfo worked as an illustrator and collector for Jose Bonaparte at the same time that Luis was Bonaparte's student. Rodolfo is a tall, lanky, easygoing man who now serves as the director of the Carmen Funes Museum, located in the town of Plaza Huincul, about an hour's drive west of Neuquen. He had moved to Plaza Huincul from Buenos Aires to be closer to the rich dinosaur deposits of Patagonia. Rodolfo and his team of fossil hunters from the Carmen Funes Museum have helped to discover and describe many new dinosaurs from Neuquen, including one of the largest animals ever to walk on earth, Argentinosaurus, and a ferocious meat-eating dinosaur,

Giganotosaurus, which rivaled Tyrannosaurus rex in size. Through Rodolfo's tireless efforts, the Carmen Funes Museum now occupies a prominent position on the international map for vertebrate paleontology.

In the earlv decades of fossil collecting, permits were not required, and foreign crews simply went into other countries and took title to whatever they found. Today, however, most countries have understandably passed laws to protect their paleontological heritage from foreign exploitation. Thus, before one travels to another country to collect, one must get permission in written agreements or permits that stipulate how the fieldwork and research will be conducted. Our agreement with Rodolfo and the Argentine authorities allowed us to prospect and collect in all the areas that we were interested in. If we were fortunate enough to find fossils, the agreement allowed us to bring the fossils to the United States to clean, cast, and study them. After the research for scientific articles was completed, the specimens would be returned to Argentina and housed at the Carmen Funes Museum. Such arrangements are now commonly struck between museums and universities in different countries.

To fund the expedition, Luis wrote a grant proposal to the National Geographic Society, describing how we wanted to prospect for fossils around Auca Mahuida. Such proposals must document the goals of the project and the potential for finding new specimens that could improve our scientific knowledge. Based on the exploratory trip taken in 1996 and the wealth of new material being discovered in the region, we believed that a grant to explore the area in more detail could be justified. As part of the proposal, Luis had to itemize a budget for our equipment and travel, and after reviewing the proposal, the Society approved it. In addition, Lowell raised money from the InfoQuest Foundation in California. In all, we raised almost $20,000 for the expedition. Rodolfo and his colleagues from the Carmen Funes Museum provided additional vehicles and equipment.

After many months of homework and planning, we were at last ready to search for ancient fossil birds and other animals in the remote badlands of Patagonia.

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