MAMMOTH UNDERTAKING : PREHISTORIC BONE YARD IN MEXICO YIELDS REMAINS FROM VARIETY OF ICE-AGE WILDLIFE.

Byline: Bill Cormier Associated Press 

Joel Aviles and some fellow workers were digging a hole for a water tank when their picks hit something hard in the muddy, gray earth.

``We dug some more to see what it was, and that's when we found the skull,'' he said. ``We were stunned.''

No ordinary skull, it belonged to a mammoth that lived 10,000 to 50,000 years ago. When scientists were called in, they discovered one of central Mexico's biggest mammoth graveyards.

While skulls and bones of mammoths have turned up previously around nearby Lake Texcoco, those finds were nothing like the July 29 discovery in San Miguel Tocuila, which is 20 miles east of Mexico City.

Already, a pit about 15 feet deep beside a cornfield has yielded bones from at least eight mammoths - including three skulls - as well as fossilized bones of ancient bison, flamingos and other wildlife.

``The find in San Miguel Tocuila is extraordinary,'' said Dr. Joaquin Arroyo Cabrales of the National Institute of Anthropology and History. ``When we first got the call, we thought it would be just one mammoth skull.''

Arroyo said the scientists learned that since 1945 villagers had not reported at least a dozen earlier finds of mammoth bones, mostly bits and pieces.

Mammoths flourished during the ice ages. For millions of years, they roamed the North American continent and southward. Then they died out just as prehistoric hunters were spreading over from what is now Siberia, scientists theorize.

Some scientists think the huge beasts were hunted to extinction.

Mexican paleontologists hope studies at the site in this high valley will provide new clues about the huge beasts.

A team led by Arroyo and archeologist Luis Morett of the Autonomous University of Chapingo are seeking to determine when these Tocuila mammoths lived, whether humans co-existed and how the mammoths died.

``We are looking for evidence of human activity, though none has been found thus far,'' said Eduardo Corona, a researcher with Arroyo at the Paleozoology Lab of the National Institute of Anthropology and History.

Daniel Fisher, a University of Michigan paleontologist not involved in the find, said the fact that several mammoths had been found at one site could yield data about their movements, feeding habits and even climate changes.

``Interpreting growth layers in their tusks and teeth can say things about their age at death, their diets, the climates they experienced from year to year,'' said Fisher, a self-described mammoth hunter.

Along with the scientists have come tourists.

People stream into town on the weekends to peer at the skulls and giant tusks of what once were beasts weighing four tons or more.

``They're just enormous

I've never seen anything like this

'' said Laura Estrada, as her 8-year-old niece Rosa tiptoed to squint through a chain-link fence into the pit.

With trunks and lengthy tusks, prehistoric mammoths were closely related to present-day elephants. Some measured more than 14 feet high at the shoulders.

``Oh, it's so much bigger than an elephant

'' said Rosa, admiring tusks twice her height and yellowed teeth as big as bowling balls.

Celso Ramirez, the owner of the property, had already built a small restaurant on his land before the discovery - and now feeds gawkers.

``It's been fascinating watching the archeologists. Every day they find something new,'' said Maria del Carmen Patino, the restaurant's cook, hawking tortillas and soft drinks to passers-by.

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Photo

Photo: Workers appear small next to a mammoth skull uncovered at an excavation site in Mexico. The remains are believed to be 10,000 to 50,000 years old.

Associated Press