Geoscience Reference
In-Depth Information
Every year, international expeditions scout some of the most inhos-
pitable 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 incred-
ible assortment of dinosaur fossils over the previous century. The sci-
entific 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 col-
leagues 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 paleontolo-
gists, 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 Pata-
gonia 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 vol-
cano 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 stud-
ied them while compiling his dissertation on ancient Mesozoic birds
from South America. Over the last few years, the origin and early evo-
lution 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
