The skeleton of a mammoth has been found in Prince George's County.

As mammoths go, it is not so big, maybe 10 feet tall at the shoulder, probably a teen-ager, scientists say.

But it definitely is a mammoth. And anthropologists, paleontologists, geologists and archeologists are running around the site like drops of water on a hot skillet.

They say the only other Maryland mammoth -- not counting the odd bone here and there -- was found in 1869 in Talbot County. The first American mammoth skeleton turned up in 1801 near Newburgh, N.Y., was bought by painter Charles Willson Peale and investigated by the American Philosophical Society under President Thomas Jefferson.

A week ago Sunday Dana D'Aria, a geology student at the University of Maryland, was out making up a missed field trip assignment. He was looking for cretaceous material, shells and mollusk fossils, signs that Maryland once had been submerged under the Atlantic Ocean.

"I found some shark teeth and gastropods and stuff and I was poking around on the bank of this ditch and my foot sank into the mud so I started using a hand shovel to dig myself out," D'Aria said, still caught up in the excitement of the thing. "I hit something and I thought it was a piece of wood but then I saw it was a rib. I thought maybe a cow. But I dug for two hours more and poked around and I found this shoulder blade two feet long. And then a lower jaw with a tooth. And then a tusk."

He tried to call the Smithsonian, but no one was in on a Sunday afternoon. He couldn't remember his professor's number, so he drove home and called him from there. The professor, paleontologist Peter Kranz, was out, so the student left a message. Then Kranz called back, but now D'Aria was out. He had gone back to the ditch with his family and dug up more ribs and teeth, vertebrae, 16 inches of tusk and half a pelvis.

Four phone calls later, teacher and student made contact. One look at the jaw told Kranz it was indeed a mammoth. By Monday the place was crawling with scientists from area universities and the Smithsonian.

Meanwhile, the developers whose bulldozing of the ditch had revealed the cretaceous layer in the first place, agreed to stop work for a few days -- provided the story didn't leak out and bring antediluvian thrill-seekers swarming all over the site.

The finders requested that the specific location not be made public, in order to keep amateur bone hunters and arrowhead fans to a minimum so the dig wouldn't be disturbed.

By week's end a dozen people were working on the spot, marked off in a grid of strings. A pump was draining the muddy creek bed, but it was still a scene out of World War I, with sandbags, shallow trenches and mud that seemed to have no bottom ("Look out, we're losing Gary," someone called as a man, intent on his work, gradually sank to his waist), covered everything and everyone, and sucked boots right off legs. Archaeologists were running water over a screen littered with muddy bits of this and that, in hopes of finding human artifacts.

Upstream, geologists were probing into the mud with a six-foot auger, trying to make some sense out of the earth layers. With infinite care, anthropologists were working scimitar-sized rib fragments out of the clinging mud. A Smithsonian cameraman was taking it all down on video.

"It's very important to find out if the animal was killed by other animals or by people," Kranz remarked, wiping some mud onto his beard with the back of his hand. "We'll study the bones for signs of weapons, like scrapes and cuts. If this was a bog and it drowned in that, then there might be many others in here, too. So far we've only found the one mammoth."

Yesterday, with some 60 fragments dug up, including pieces of skull and the major long bones, the mammoth dig wound down. Smithsonian anthropologist Dennis Stanford, in charge of the project, said only the one beast had been discovered.

It was most unusual, Kranz noted, to find Pleistocene deposits, which date from 2 million years up to a mere 11,000 years ago, overlapping the Cretaceous, which will take you back 60 million to 75 million years. Mammoths, which first appeared in the Pliocene epoch (2 million to 12 million years ago), only went extinct in about 6,000 B.C., which is like last week to a paleontologist. Many scientists believe human hunters did the mammoth in.

"We think the mammoth was about 10 to 15 years old and stood maybe 8 to 10 feet at the shoulder," Kranz said. "We have some tusk that's several feet long and six inches thick. We've taken the bones to the Smithsonian."

For 24-year-old D'Aria, a junior majoring in geology and wildlife management, a student of "biology and ecology and jazz like that" who once won a prize for reconstructing a deer skeleton, it was hard not to be just a little proprietary about his mammoth. "I guess the teacher was pleased," he said, in what was surely the understatement of the semester.