But early Olmec rulers were aware of the territory where the Maya eventually established imposing cities. Three years ago, scientists reported finding a rich lode of jadite, including huge boulders of it, in the jungles of Guatemala. Traces of ancient mining were uncovered, and some of the outcroppings were of blue jade, the prized gemstone Olmec artists used for carving delicate human forms and scary masks.

Archaeologists said the discovery not only solved a mystery of the origin of Olmec jade, but also showed that the Olmecs exerted wide influence over the region, either directly or by trade through intermediaries.

The Olmec influence on the Maya began to show up in artifacts, starting before 100 B.C. By then, Coe and other scholars said, Olmec art, religion, rubber-ball games and the ceremonial dress of rulers had clearly found its way to Maya cities.

Diehl said there was "good evidence that Olmec sculpture is portraying beliefs" also related in Popol Vuh, the epic of creation found in Maya writing. This cosmology predated the Maya and was widespread in Mesoamerica, but its origins are murky.

The classic maize god of the Maya, scholars say, appears to be a clear descendant of a similar Olmec god. A Maya wall painting in San Bartolo, Guatemala, shows a resurrected maize god surrounded by figures offering him gifts of tamales and water. "The deity's head is purely Olmec," Coe said. The assumption is that aspects of Olmec culture reached the Maya indirectly, probably through what is known as the Izapa civilization in the territory extending from the Gulf Coast across to the Pacific Coast of Chiapas, in Mexico, and of Guatemala. The city known as Izapa is the site of imposing temple mounds in Chiapas, a place where the Olmec sculpture and Maya painting and glyphs seemed to converge.

John E. Clark, an archaeologist at Brigham Young University, has excavated in the area for years and is involved with current research, he said, showing strong links between San Lorenzo and ancient sites in Chiapas.

From there, Clark said, the influence of the Olmecs — not only their art and gods but their kingship and all its trappings — eventually penetrated deep into Maya country and its rising cities. It appeared to be a melding of late Olmec culture with preclassic Maya. Some early carvings of Maya kings, he said, were made on the backs of Olmec jade pieces. A comparison of their art reveals that Maya and late Olmec kings dressed in similar style, resplendent in jade and feather capes like their shared gods.