Ancient pottery found at an altar used by ancient Greeks to worship Zeus was actually in use at least a millennium earlier, new archeological data suggest.

The pottery shards were discovered during an excavation last summer near the top of Mt. Lykaion in southern Greece.

The finding, which dates back to 3000 B.C., indicates that the tradition of divinity worship on the site is very ancient and may even pre-date the introduction of Zeus into the Greek world, said David Gilman Romano, a researcher at the University of Pennsylvania Museum of Archaeology and Anthropology and co-director of the excavation project.