Last month, in their second season at the site of an ancient settlement in southern Mexico, archaeologists digging into the ruins of a pyramid came upon a row of large, flat stones -- the wall of a tomb. Inside, they found skeletons of a prominent man, possibly a ruler, and two human sacrifices. Another apparently elite adult was on a landing just outside the tomb.
The archaeologist in charge, Bruce R. Bachand of Brigham Young University in Utah, determined from the style of ceremonial pottery in the tomb that the burials occurred about 2,700 years ago. He said that could be several centuries earlier than any richly decorated burials previously found in Mesoamerican pyramids.
Dr. Bachand said recently in an interview by telephone from the site that the two principal skeletons bore the hallmarks of persons "at the very top of society." The one in the tomb was coated with red pigment and adorned with hundreds of jade ornaments, the teeth inlaid with white jade or marine shell. The skeleton outside the tomb, possibly that of a woman, was decorated with jade, pearl and amber, and the upper teeth inlaid with pyrite, commonly known as fool's gold. The sacrificial skeletons, an adult and a child, were unadorned and lacked ritual offerings.
Anthropologists who specialize in pre-Columbian cultures of Mexico and Central America said it was premature to assess the find's full significance but agreed with Dr. Bachand that it was an important early example of social ranking in the region's cultures and the rising political centralization under chiefs.
The discovery was made near the top of a 30-foot-tall pyramid, the highest structure at the central plaza of the ancient site at Chiapa de Corzo in the state of Chiapas, not far from the Guatemala border. The excavations were supported by the National Geographic Society.
The tomb raised a difficult question: What culture was responsible for it? At the time, around 700 B.C., the region was occupied by several societies trading and raiding, exchanging traditions and ceramics and otherwise interacting. Their elites forged alliances and perhaps intermarried.
The Olmec, renowned for their monumental sculpture, spread their influence far inland from their base on the Gulf Coast and were once thought to be the dominant culture. The Maya were emerging in the south. Around Oaxaca, the Zapotec were creating an advanced culture. And Chiapas was home then, as it still is, to people sharing the Zoque language.
Dr. Bachand noted that many artifacts in the tomb were similar or identical to those found at the imposing Olmec ruins of La Venta, in Tabasco. "Did these people come from La Venta?" he said. "Or were they local people who simply reflected their interactions with the Olmec? This is the $10 million question."
But aspects of the burials differed from the Olmec culture, he said. Some pottery and ritual practices appeared to be in an indigenous style. The tomb's construction -- a stone wall on one side, clay on the others -- was unlike that of the few known Olmec tombs.
In a preliminary interpretation, Dr. Bachand said the culture of the tomb builders had Olmec roots, suggesting a need for further research at La Venta. But he raised the possibility that the discovery evoked beginnings of a distinct Zoque culture, in which case, he said, the origin of some early Mesoamerican traditions may not be Olmec or Maya but Zoque, a previously underrated society.
Elsa M. Redmond, an anthropologist at the American Museum of Natural History in New York, said evidence from the Chiapa de Corzo tomb "definitely supports" an emergent consensus among Mesoamerican scholars that the Olmec influence in this formative period, though widespread, was not singular. The view of the Olmec as a "mother culture," she said, has been generally replaced by a "sister culture" model.
This school of thought, elaborated by Kent V. Flannery and Joyce Marcus, anthropologists at the University of Michigan, holds that many contemporaneous cultures in ancient Mexico shared technologies and traditions arising not so much from one source, like the Olmec, as from independent responses to needs and beliefs or through a complex mix of social and economic interactions.
In these "parallel developments," Dr. Redmond said, "similar kinds of architecture, ritual and elaborate tomb paraphernalia appeared in their particular cultures."
She praised Dr. Bachand's excavations at a site that has long been neglected, and was curious to find out the identity of the woman on the landing beyond the inner sanctum. If she was the ruler's wife, as her lavish accouterments might indicate, why was she left to spend eternity outside her husband's tomb?
This article originally appeared in The New York Times .