But for decades, archaeologists have argued over the birth of the culture that spawned those splendid cities about 1000 BC.

• Did Maya society spring from the Olmec civilization of Mexico's Gulf Coast, known for its colossal carved stone heads?

• Or did it emerge independently through some local process?

A new analysis of items from a long-buried ceremonial structure in central Guatemala supports a third hypothesis, researchers reported Thursday - that lowland Maya culture grew out of an amalgam of influences from nearby settlements.

"The origin of Maya civilization was more complex than previously thought," said Takeshi Inomata, an archaeologist at the University of Arizona in Tucson and lead author of a study detailing the analysis in the journal Science.

In his view, the culture that went on to dominate Mesoamerica until the arrival of Europeans got its start during a power vacuum that lasted for about 200 to 350 years in a period of Olmec rule.

 

That allowed the people who built the ceremonial structure at a site known as Ceibal to interact with others from nearby areas and begin forming a new culture.

 

They probably had influences from as far away as Chiapas and the Pacific Coast, both about 200 miles away.

"Ceibal was a part of this major change," Inomata said.

Takeshi Inomata has been working at Ceibal, in the southwestern Maya lowlands, since 2005.

 

 

 

 

The people who lived there repeatedly built on the same site over hundreds of years, leaving behind layers of civilization that extend 30 feet or more beneath the surface.

 

Digging deep to gain access to ancient construction, Inomata and his team - which included his wife, Daniela Triadan, also of the University of Arizona - discovered a collection of structures that archaeologists refer to as "E-Group assemblages."

 

There was a square building on the west, an open plaza and a long platform on the east. By 700 BC, the building was as much as 26 feet tall.

 

These types of structures are considered precursors of the monumental pyramids that the Maya later built at sites such as Palenque in southern Mexico. Aligned with the sun's path through the sky, such buildings are believed to have been ritual spaces where the community would have gathered to make offerings.

 

The team discovered many axes made of green stone at the bottom of the Ceibal plaza - tools that would have been "really valuable for these people" and are thought to be offerings, Inomata said.

 

To figure out the age of these structures, the team ran carbon-dating tests on dozens of samples of wood and human bone remains from the site.

 

Using sophisticated statistical models to refine the dating of 54 of the wood samples, they determined that the E-Group at Ceibal dated to 1000 BC - about 200 years earlier than most Maya settlements that adopted the E-Group architecture, Inomata said.

 

The bones dated as even older, but the researchers didn't include them in the calculations because eating fish can skew the results. That makes the Ceibal buildings the earliest known example of the architecture.

 

And based on the researchers' understanding of the age of the Olmec center at La Venta, which also had E-Groups, they concluded that Ceibal's ceremonial plaza and buildings were constructed first.

"Ceibal's beginning was before La Venta became a big center," he said. "As a small center, it couldn't have been the source of major influence."

But that doesn't mean that Ceibal had to be the origin of the ceremonial architecture, Inomata added.

 

Sites in Chiapas and on the Pacific Coast have similar architecture, and they arose in the same period, he said.

"There's this very standardized pattern, so we assume there was close contact between those people," he said. "They were visiting each other. And that close contact was the process for the cultural innovation."

Washington University anthropologist David Freidel, who was not involved in the research, called the study "a benchmark contribution." But he said the issue of Olmec influence remained unresolved and that archaeologists would continue to present evidence disputing the La Venta dates.

 

The debate,

"is kind of like a game of tennis," he said. "You watch the point go back and forth between areas - who was the earliest? - as we explore origins of complexity in the society."

Robert Rosenswig, an archaeologist who specializes in Mesoamerica at the University at Albany, State University of New York, said the discovery that 1000 BC was an important time in the development of Ceibal fit well with his research into the reliance on corn as a staple food among people in the region, which occurred about the same time.

"There seems to have been this major transformation not only in architecture but in the whole subsistence base," said Rosenswig, who also was not involved in Inomata's work. "The two are probably related."

Inomata's research was funded by,

• the National Geographic Society

• the National Science Foundation

• other U.S. and Japanese sources