For decades, evidence from ancient caves suggested that the world's first works of art were created by modern humans when they arrived in Europe about 40,000 years ago, but new research has revived the possibility that the early craftsmen may have been Neanderthals.

Archaeologists using modern dating techniques showed that the supposedly ancient remains of modern humans found buried in a cave in Vogelherd, in southwest Germany, were only between 3,900 and 5,000 years old, far younger than the lovely figurines that someone carved inside the cave more than 30,000 years ago.

Vogelherd, world famous since its discovery in 1931, was the last significant site that had directly linked modern humans with "Aurignacian" artwork and tools from the period between 30,000 and 40,000 years ago when humankind first made objects with aesthetic as well as utilitarian purposes.

"Vogelherd has dated young, like several other sites," said paleoanthropologist Nicholas J. Conard of Germany's University of Tubingen. "Now we're in the uncomfortable position of having a question and no answers."

The Aurignacian culture encompasses several millenniums when modern humans coexisted in Europe with Neanderthals, the Ice Age predecessors who had lived there for at least 100,000 years.

Neanderthals became extinct about 30,000 years ago. How this happened -- whether through disease, intermarriage or obliteration by their cleverer successors -- is one of anthropology's persistent mysteries.

"For years, the thinking was that in the Aurignacian -- with its evidence of art, musical instruments and ornaments -- we were dealing with people like you and me," Conard said in a telephone interview from his Tubingen office. "If Neanderthals were doing it, that would be a shock."

But possible. "This is a good thing, because it shows that maybe you should be careful what you take for granted," said University of California paleoanthropologist Clark Howell, in a telephone interview from Berkeley. "I would argue that there are still a few bits and pieces [of human remains] that have passed all the tests. They are not Neanderthal, but they're not conclusive, either."

Conard, reporting in this week's issue of the journal Nature with co-authors Pieter M. Grootes of the University of Kiel and Fred H. Smith of Loyola University of Chicago, reexamined the work of Gustav Riek, the pre-World War II German archaeologist who excavated Vogelherd before modern radiocarbon and spectrographic dating methods were invented.

Previously dated animal bones from the cave were more than 30,000 years old -- contemporary with a dozen figurines found in the cave. "There's no question they're Aurignacian," Conard said. "The figurines are mammoth, wooly rhinos, horses, reindeer -- Ice Age animals."

The human remains, however -- a skull, a jawbone, a thigh, an upper arm and two vertebrae -- proved to be much younger, "intrusive" objects buried beneath the older artifacts. "Riek was very famous, but it seems clear that while he was digging, he messed it up," Conard said. "I have no reason to believe he falsified his results."

Conard described the Vogelherd cave as the "last linchpin" tying modern humans to Aurignacian artifacts. Without Vogelherd, experts are left in an odd situation in which there are no significant human remains -- modern or Neanderthal -- that can be linked to any Aurignacian artifacts.

"It's amazing how few human remains there are," said University of Arizona archaeologist Steven Kuhn, reached by telephone in Ankara, Turkey, where he is working on an excavation. "It could be a change in burial custom. Or it could be that we just haven't found the sites."

He said his own excavation would not resolve the dispute: "It's a 40,000-year-old site with lots of ornaments," he said. "But there are no human fossils associated with it. We wish we knew who lived there."

Kuhn was skeptical about the possibility that Neanderthals created the early artwork, noting that for tens of thousands of years in Europe "they're not doing this, then suddenly they are? It points to something extraordinary happening, either the arrival of modern humans or something else" as yet unknown.

New York University's Randall White, working this summer in France, also noted the growing evidence that while Neanderthals sometimes buried their dead in their homes, they never buried them with artifacts. He added that there is virtually no evidence that Neanderthals made artwork in any context.

"There is no association of Neanderthal remains with Aurignacian artifacts," White said in a telephone interview from Bordeaux. But, he added, "that said, it would not surprise me to find some."

He acknowledged that the Vogelherd findings had somewhat undercut the argument in favor of modern humans as the ancient artisans.

"We don't understand what [modern humans] did with their dead," White said. "Maybe you don't bury them, but you transform them into ornaments instead. Or maybe you take them out to the woods and bury them there. We'd never find them."

Archaeologists reexamined Gustev Riek's work at Vogelherd, where Riek excavated this skull in 1931.