Stone Age artists were painting red disks, handprints, clublike symbols and geometric patterns on European cave walls long before previously thought, in some cases more than 40,000 years ago, scientists reported Thursday, after completing more reliable dating tests that raised a possibility that Neanderthals were the artists.

A more likely scenario, the researchers said, is that the art -- 50 samples from 11 caves in northwestern Spain -- was created by anatomically modern humans fairly soon after their arrival in Europe.

The findings seem to put an exclamation point to a run of recent discoveries: direct evidence from fossils that Homo sapiens populations were living in England 41,500 to 44,200 years ago and in Italy 43,000 to 45,000 years ago, and that they were making flutes in German caves about 42,000 years ago.

Then there is the new genetic evidence of modern human-Neanderthal interbreeding, suggesting a closer relationship than had been generally thought.

The successful application of a newly refined uranium-thorium dating technique is also expected to send other scientists to other caves to see if they can reclaim prehistoric bragging rights.

In the new research, an international team led by Alistair W.G. Pike of the University of Bristol in England determined that the red disk in the cave known as El Castillo was part of the earliest known wall decorations, at a minimum of 40,800 years old.

That makes it

the earliest cave art found so far in Europe, perhaps 4,000 years older than the paintings at Grotte Chauvet in France.

In a report published online in the journal Science, Pike and his colleagues noted that the oldest dated art is "nonfigurative and monochrome (red), supporting the notion that the earliest expression of art in Western Europe was less concerned with animal depiction and characterized by red dots, disks, line and hand stencils." The more stunning murals of bison and horses came gradually, later.

Although the early dates coincide with recent evidence of a Homo sapiens presence in Europe, the scientists wrote that because 40,800 is only a minimum age "it cannot be ruled out that the earliest paintings were symbolic expressions of the Neanderthals."

Other scientists were expected to be skeptical, pending more evidence of even earlier dates for cave art or of painting associated with Neanderthal tools or fossils. Eric Delson, a paleoanthropologist at Lehman College of the City University of New York, said, "There is no need to hypothesize that Neanderthals created these paintings, as we have evidence of artistic Homo sapiens already in Western Europe."