Discoveries At Teotihuacan's Pyramid Of The Moon Help Unlock Mysteries Of Western Hemisphere's First Major Metropolis

Announced today, the latest discovery at the site is a tomb apparently made to dedicate the fifth phase of construction of the pyramid, containing four human skeletons, animal bones, large conch shells, jewelry, obsidian blades and a wide variety of other offerings. Excavation is expected to continue for another two weeks.

Found by a team of archaeologists led by Saburo Sugiyama, associate professor at Aichi Prefectural University in Japan and adjunct faculty at Arizona State University, and Ruben Cabrera of Mexico's National Institute of Anthropology and History, the burial contains important evidence that may help archaeologists define and examine a particularly active period in Teotihuacan's history and perhaps one of the culture's "defining moments."

The tomb and its offerings appear to differ in important ways from another dedicatory tomb found at the site a year ago. That tomb, clearly associated with the pyramid's fourth stage of development, contained only one human male -- a bound, sacrificial victim -- as well as wolf , jaguar, puma, serpent and bird skeletons, and more than 400 other offerings, including large greenstone and obsidian figurines, ceremonial knives, and spearpoints.

"The contents of this new burial appear to be significantly different from the tomb we found last year," said Sugiyama. "But there are many aspects to this burial that seem similar to those we found a decade ago in the tombs under the Feathered Serpent Pyramid."

Sugiyama notes the presence of many green obsidian blades in the new burial -- a color of obsidian lacking in the tomb in pyramid four, but common in the Feathered Serpent burials -- and the presence of a greenstone "butterfly" nose pendent that is "exactly the same style as the ones we found at the Feathered Serpent Pyramid."

There also are more military items among the offerings, and a larger number of human sacrifices, both of which are reminiscent of the Feathered Serpent burials, where they found more than 130 human skeletons, most of them clearly soldiers and possibly war captives.

"As a result of the final discoveries, we find explicit signs of militarism in the culture since its early periods," said Sugiyama.

Beyond the offerings, there are other indications as well of a cultural shift occurring between the two burials.

The current find appears to be connected to the phase in the pyramid's development that followed the building of pyramid four-- a distinct stage in the structure's history that has not been recognized until now. The inhabitants of Teotihuacan built successively larger pyramids on top of the previous monuments, often partially deconstructing the previous pyramid in the process. From past research, there were thought to have been five phases to the Pyramid of the Moon, with phase one (dated in the 1st Century A.D.) being Teotihuacan's oldest major monument. Excavations show a major jump in size and complexity occurring with the construction of pyramid four and a change in orientation that puts it in line with the unique and precise city grid structure that we see today in the city's eight square miles of ruins.

Sugiyama and Cabrera have found evidence indicating that a significant remodeling of pyramid four -- a fifth period of construction -- occurred before the pyramid received its final addition. This new fifth stage, which contains the recently discovered tomb, appears to be a significant modification of the fourth structure's architecture, position and size. Part of the remodeling involved the first use on the Pyramid of the Moon of the "talud-tablero" architectural style that dominates the structures we see today, including the Feathered Serpent Pyramid and the Pyramid of the Sun, in its "Adosada" portion.

Evidence in the differences in the ceremonial offerings between pyramid four and its remodeled version, pyramid five, thus suggest an important shift in the culture that may also be reflected in the construction of the Feathered Serpent Pyramid and the Pyramid of the Sun. Both of these pyramids were constructed largely at one time and are newer than the earlier phases of the Pyramid of the Moon.

"There's not enough data yet to draw any large conclusions, but one thing that's fascinating is that the mythic images that we see in the war-like murals from late periods of Teotihuacan -- jaguars, coyotes and eagles with shells and head dresses -- are made up of elements that we see literally present in these much older burials," said Sugiyama. "What was going on here seems to have had a lasting effect."

Though archaeologists have long been fascinated with the site, Teotihuacan's culture and history are still largely mysterious. The civilization left massive ruins, but no trace has yet been found of a writing system and very little is known for sure about its inhabitants, who were succeeded first by the Toltecs and then by the Aztecs. The Aztecs did not live in the city, but gave the place and its major structures their current names. They considered it the "Place of the Gods" -- a place where, they believed, the current world was created.

At its peak around 500 A.D., Teotihuacan contained perhaps 200,000 people, a master-planned city covering nearly eight square miles and larger and more advanced than any European city of the time. Its civilization was contemporary with that of ancient Rome , and lasted longer - more than 500 years.

The current excavation under the Pyramid of the Moon may be one of the best opportunities to answer questions about the civilization, as its underlying older, primitive loose rock construction may have protected buried secrets by making it difficult to dig under and resistant to looters. Sugiyama hopes to find still more tombs. "We have noticed that this tomb is a few feet to the east of the city's north-south axis line," said Sugiyama. "These people were generally very precise and they rarely did anything unsymetrically. With this in mind, we can suspect to find other burials based on our precise maps."

The excavation is a joint project of the ASU Department of Anthropology and Mexico's National Institute of Anthropology and History and is funded in part by grants from the National Science Foundation and the National Geographic Society. Study and analysis of the burial items and other materials found in the excavation will be conducted at the ASU Archaeology Center in nearby San Juan Teotihuacan. The center, which has quarters and laboratory space for ten archaeologists, was founded with the help of an NSF grant in 1987 to do research on Teotihuacan.