SAN JUAN - US and Puerto Rican archeologists say they have found the best-preserved pre- Columbian site in the Caribbean, which could shed light on virtually every aspect of Indian life in the region, from sacred rituals to eating habits.
The archeologists believe the site in southern Puerto Rico might have belonged to the Taino or pre-Taino people that inhabited the island before European colonization, although other tribes are a possibility.
It contains stones etched with ancient petroglyphs that form a large plaza measuring about 130 by 160 feet, which could have been used for ball games or ceremonial rites, said Aida Belen Rivera, director of the Puerto Rican Historic Conservation office.
The petroglyphs include the carving of a human figure with masculine features and frog legs.
Archeologists also uncovered several graves with bodies buried facedown with the legs bent at the knees - a style never seen before in the region.
The plaza might contain other artifacts dating from 600 A.D. to 1,500 A.D., including piles of refuse from daily life, Rivera said.
"I have visited many sites and have never seen a plaza of that magnitude and of those dimensions and with such elaborate petroglyphs," said Miguel Rodriguez, a member of the government's archeological council and director of a graduate school in Puerto Rico that specializes in history and humanities.
Archeologists have known since 1985 that the area contained indigenous artifacts. But their extent and significance only became clear this month after the Army Corps of Engineers began work on removing them so the land could be used for a dam project.
Specialists called for a halt to the excavation, saying the use of heavy machinery exposed the stones to the elements and could have destroyed important artifacts. The Corps of Engineers has said the site will be preserved.
The Tainos were a subgroup of the Arawak Indians, who migrated to the Caribbean from Mexico's Yucatan centuries before European colonizers arrived.
Jose Oliver, a Latin American archeology lecturer at University College London, said that archeologists make discoveries of this significance every 50 or 100 years - if they are lucky.
The lead investigator for New South Associates in Georgia, the archeological and historical consulting firm leading the excavation, said that a back hoe that scrapes inches at a time did break some bones, but that the same would have occurred through manual excavation.
The company switched to slower and more detailed excavation methods about two weeks ago, after the site's significance became clear, investigator Chris Espenshade said.