Jurassic Park ended in disaster and chaos, but that isn't stopping scientists who are proposing to clone a 23,000-year-old woolly mammoth they found in the Siberian Arctic last fall.

After a winter of cold storage, the team is preparing to thaw the woolly mammoth - which remains frozen in the 23-ton block of ice that encased it when it was found. The Discovery Channel, which financed the expedition, will show a special on the mammoth at 8 p.m. tomorrow.

Meanwhile, other scientists are attempting to clone everything from rare oxen to wild cats.

The male mammoth, which researchers estimate died at age 46, could offer new clues about these giant elephant cousins that roamed much of the planet during the Ice Age before vanishing mysteriously 10,000 years ago, perhaps at the hands of human hunters.

"If the [skin and cell] samples are good and make it home and remain intact, who knows what secret may be learned of the behemoth of the Ice Age?" the film's narrator says.

But despite Discovery's hopes, successful cloning is virtually impossible, scientists familiar with the challenges of cloning less-exotic beasts say.

The freezing issue isn't the problem. Dolly the sheep was cloned from frozen sheep tissue - but in her case, the tissue was carefully handled and quickly frozen.

Even under the best of circumstances, said biologist Alex Greenwood of the American Museum of Natural History in New York, the mammoths began to decay long before they froze. "It's like a giant road kill," he said.

More damage accumulates over the centuries as the body gets dried out and suffers freezer burn, he said. "Even the well-preserved flesh is like beef jerky."

There's still some DNA in the jerky, Greenwood said, but cloning requires not just DNA, but the entire nucleus of an animal cell, with the DNA neatly packaged in chromosomes.

All scientists have ever gotten from dead mammoths has been ripped-up DNA whose genetic code has been partly corrupted, Greenwood said. "The DNA is in lousy shape even in the best-preserved mammoths," he said.

"They'll need a viable cell," agreed Robert Lanza, a biologist who specializes in cloning at the Worcester, Mass.-based company Advanced Cell Technology.

The other possibility would be to extract sperm from the mammoth and artificially inseminate a live female elephant. But, again, the skeptics say it's unlikely they will get viable sperm after more than 20,000 years, and even if they do, the offspring would only be half mammoth.

Cloning expert Lanza agrees that getting intact cells is unlikely. But if the French-American team did get such cells, he said, it could clone the creature by taking the nucleus from a mammoth cell and injecting it into an egg extracted from an elephant. An elephant surrogate mother could carry the developing mammoth.

Lanza said his company was the only one in the world trying to clone the DNA from cells of one species with the egg cell of another. Advanced Cell Technology gained notoriety in 1998 when its scientists inserted a human cell nucleus into the egg of a cow and turned it into what appeared to be a human pre-embryo.

The company has not taken human-cow work any further, but it is engaged in cross-species cloning with endangered animals and one extinct one. In one experiment, researchers took DNA from a rare breed of ox, inserted it into a cow egg, and implanted what appear to be healthy embryos into cows.

In a similar experiment, they are using the eggs of ordinary house cats to clone an endangered wild one, the desert cat. The company's scientists are also doing the groundwork to clone the first giant pandas using the eggs and uterus of either a dog or a raccoon.

Lanza said these experiments cannot do much to help wild species whose habitats have been destroyed, but they can keep individuals alive for zoos.

Greenwood questioned, however, the value of re-creating animals too long extinct to be anything but zoo exhibits.

"There are a whole slew of animals - moas, dodoes, that are more recently extinct," he said. ". . . It seems sort of crazy to me when you have animals like cheetahs or tigers that are endangered."

But DNA might hold further clues to the animals' pasts, Greenwood said.

What Greenwood wants to know is why the mammoths went extinct about 10,000 years ago. One theory holds that climate changes at the end of the Ice Age led to their demise. Others suggest that since the mammoths died shortly after humans came to America, they may have been hunted to death.

Greenwood thinks a virus did the woolly mammoth in. The trick, he said, would be to study enough mammoths to pinpoint the virus.