Unlike its larger, postcard-perfect neighbors in the Aegean Sea, Keros is a tiny rocky dump inhabited by a single goatherd.

But the barren islet was of major importance to the mysterious Cycladic people, a sophisticated pre-Greek civilization with no written language that flourished 4,500 years ago and produced strikingly modern-looking artwork.

A few miles from the resorts of Mykonos and Santorini, Keros is a repository of art from the seafaring culture whose flat-faced marble statues inspired the work of 20th century masters Pablo Picasso and Henry Moore.

Indeed, more than half of all documented Cycladic figurines in museums and collections worldwide were found on Keros. Now, excavations by a Greek-British archaeology team have unearthed a cache of prehistoric statues -- all deliberately broken -- that they hope will help solve the Keros riddle.

When they were unearthed, the white marble shards were jumbled close together like a pile of bleached bones, an elbow here, a leg there, occasionally a head.

British excavation leader Colin Renfrew now believes Keros was a hugely important religious site where the smashed artwork was ceremoniously deposited.

"What we do have clearly is what must be recognized as the earliest regional ritual center in the Aegean," he said.

This could put it on a par with the sacred islet of Delos -- also in the Cyclades -- revered from early antiquity until Christian times as the birthplace of Apollo, god of music and light. The finds on Keros date to about 1,500 years before the cult of Apollo started on Delos.

There is no evidence the Cycladic culture worshipped the Greek gods of Mount Olympus, who first appeared in the 2nd millennium B.C., and their beliefs are shrouded in mystery as no sanctuaries dating to before 2000 B.C. have been excavated.

However, some experts think the islanders' religion was probably built round a fertility cult tied to the mother-goddess of Neolithic times, whose worship survived in various forms until Christian times in the Greco-Roman world. The Cycladic statues, many depicting pregnant women, may have played a part in such beliefs, and their deliberate destruction would have been a ritual act.

During excavations in the spring and early summer, Renfrew's team found an undisturbed trove of figurines missed by looters who ransacked the islet in the 1950s and 1960s. They all had been deliberately smashed around 2500 B.C.

"We've got hundreds of marble bowl fragments and many dozens of figurine fragments, which don't seem to fit together," said Renfrew, an emeritus professor of archaeology at Cambridge University and former director of the McDonald Institute for Archaeological Research.

"You have a head here, a single foot here, a torso there, some thighs here -- and all very deliberately broken. Pieces have been deliberately broken again into small pieces."

The Cycladic culture -- a network of small, sometimes fortified farming and fishing settlements that traded with mainland Greece, Crete and Asia Minor -- is best known for the elegant figurines: mostly naked, elongated figures with arms folded under their chests. It flourished in 3200-2000 B.C., then was eclipsed by Crete and Mycenaean Greece.

A group of broken figurines like that found this year is known from private collections formed after the looting. But for the first time, experts can now try to piece a story together from the subtle clues that treasure hunters destroy.

The excavation disproves theories that the artifacts came from cemeteries -- as no human bones were found -- or were wantonly broken by modern vandals.

"We can say that the breakages are definitely old," Renfrew said. "(The figurines) weren't smashed there because (then) you'd find the bits together. And there's differential weathering, which suggests that not only were they broken elsewhere and brought there, but some of them became weathered elsewhere."

Renfrew believes the figurines -- some originally up to a yard high -- may have come from sanctuaries throughout the Cyclades. And pottery finds indicate the site could have attracted worshippers from as far away as mainland Greece.

"Maybe at some point in some life cycle, the figurines were ritually smashed and taken to Keros in some ceremony," he said. "It's going to take a while to sort out what's going on."

Experts agree the figurines, which initially had details painted in bright colors, were highly prized in the early bronze age Cyclades, but still don't understand what they were made for. Some 1,400 have survived, although only 40 percent are of known origin, since looters destroyed evidence on the rest.

The figurines were made following a pattern that changed little over 800 years. They have been variously interpreted as depicting gods or venerated ancestors, serving as replacements for human sacrifice, grave goods -- even children's toys.

While Renfrew believes they should not be associated with the cemeteries many were found in, he concedes there is little evidence of how they were used in everyday life.

"So there's a lot we have yet to learn," he said. "We may be on the path towards learning now."