Scientists as far back as 1871 were convinced the Archaeopteryx, a homely looking bird with claws at the top of its wings and a decidedly duck-like bill, was a very special animal.

Some went so far upon discovery of the first fossil in Europe that year to call it the world's first bird. Others called it fabled, suggesting it was straight out of the pages of ancient myths.From impressions it left behind in shale 150 million years ago during the Jurassic geological period, this low-flying creature apparently had feathers, a feature that firmly secured it in scientific history as a bird.

But there were other things 19th century researchers saw-unusual bone structure, claws and of course its bill. Still, the consensus was "bird" in 1871 despite characters that surely could have deemed Archaeopteryx some sort of flying reptile.

Now, avian paleontologists, scientists who study the remains of ancient feathered creatures, say the researchers of a century ago were right.

They believe it is the missing link in the evolution of birds from reptiles.

"It was about the size of a chicken, if you really want to get an idea of how it compares to birds today," explained West German Archaeopteryx expert Peter Wellnhofer at a recent lecture in Los Angeles on ancient birds.

"It had feathers and was in every aspect a bird. You wouldn't mistake it for anything else if it happened to fly onto your window sill one morning."

That is, until it opened its mouth.

Archaeopteryx, as it turns out, had a full set of teeth.

"That's one of the features that is more reptilian than avian," said Willnhofer."There are no living birds with teeth or other characters in its skeleton to indicate a close relationship with Archaeopteryx. That is why we often say that it is the world's first bird."

Scientific interest in Archaeopteryx was revived last year when scientists accidentally happened upon a skeletal speciman in the Solnhoffen Museum of Natural History in West Germany.

The fossil had been neglected and was not even identified, to the surprise of scientists like Wellnhofer and others who had been searching for years for the perfect Archeopteryx remains.

"You can only imagine our shock when this was verified as a true Atchaeopteryx fossil," he said. "It is about 10 percent larger than the London specimen which had been the largest one known. And it was in very, very good condition.

"I consider this one to be of the same genus," as the fossil on display in London which was discovered in Bavaria in 1871, he said.

Kenneth Campbell, curator of vertebrate paleontology at the Natural History Museum in Los Angeles, said many ancient birds shared such common features as teeth and prehensile claws on their wings. All of these features have since evolved out because they are no longer useful.

One example, he said, is Osteodontoris orri, a large extinct marine bird that ranged over what is now Southern California and is related to the modern day albatros.

This ancient feathered creature had a wingspan of 16-feet and like Archaeopteryx had a full set of bony teeth.

In fact, osteodontoris's name means bony teeth, suggesting that it not only caught fish but was quite capable of taking a bite out of them as well.

Archaeopteryx appparently lived only in Europe, was primarily vegetarian and may have had to get a running start on flight.

"All indications are that it is a very poor flyer. Its flight muscles were not well developed," Wellnhofer said, referring to studies that inferred the creature's flight capabilities from uits skeletal structure.

"From all indications, Archaeopteryx was a bird and is the oldest bird we know," apparently predating its California fish-eating relative, Wellnhofer said.

"It must have had relatives even more primitive since it has so many reptilian characters. There's no question that itc ancestors must have been reptiles.

"But unfortunately we do not have a fossil record that would provide evidence of these intermediate stages," from true reptile to a cross between reptile and bird, he said.

He said there are only six specimens of Archaeopteryx in the world and it is not easy to say if any others ever will be found.

the bird became extinct because it was replaced over time with creatures that functioned more efficiently in their various environments.

This is not to say that nature made a poor design of a bird when the Archaeopteryx came about, he said. "In its time, it was a very successful bird."