THE remains of three 10,000-year-old stone buildings unearthed near the headwaters of the Tigris River by a team of American and Turkish archaeologists may be the oldest examples of public buildings yet found anywhere in the world. This year marks the 25th anniversary of a unique collaboration - the Joint Prehistoric Project of the Universities of Chicago and Istanbul - formed to search for the beginnings of agriculture and settled village life in the foothills of the mountains ringing Mesopotamia. Project co-directors Dr. Robert Braidwood of the University of Chicago; his wife, Linda, of Chicago's Oriental Institute; and Halet Cambel of the Prehistory Department of Istanbul University chose to begin at a little mound called Cayonu Tepesi in the foothills of the Toros Mountains in southeasten Turkey. What they discovered was a prehistoric farming village. This site is distinguished from similar sites in the Middle East by the remains of the stone buildings, believed to be the earliest community structures yet found.
The craftsmanship in the construction of the buildings - including a polished terrazzo floor and a slab with a carving of a human face - so surprised the team that at first they thought they might have found Greco-Roman ruins. ``The buildings appear to be the first evidence that once people began controlling their food supply through agriculture, social change accelerated at a rate much faster than archaeologists had previously envisioned,'' Dr. Braidwood says.
Cayonu was inhabited from about 7250 to 6750 BC, a time when the environment was favorable for both specialized hunting-collecting and simple food production. The village, about 20 percent of which has now been excavated, had a population of about 500 and boasted domesticated wheat and pulses. For animal protein, the villagers hunted a now-extinct breed of wild cattle. Evidence of domesticated livestock appeared only in the latest phase of the settlement.
The villagers did not make pottery, but they did experiment with the use of copper. Cold-hammered native copper tools found at the site, including small pins and hooks, are the world's first substantial evidence of the use of worked copper (Cayonu lies barely 20 kilometers [12 miles] down slope from a copper lode that is still being mined). The residents of Cayonu also experimented with the use of cement for construction, making Cayonu a very technologically sophisticated community for its time.
``We had simply not anticipated the remarkably preserved foundations of houses, the formality of the settlement plan, the existence of public buildings, and the highly developed construction skills of people only on the threshold of effective food production,'' says Braidwood.
All three of the public buildings lie in the eastern part of the settlement and are roughly the same size. Each had a large room with the entrance apparently facing south. The flat roofs were supported by stone foundation walls with upper portions of sun-dried mud brick. There is evidence of careful plastering on some of the inner walls; traces of red paint still exist in one room. Pilasters had been placed in the walls, and in one building they were aligned with broken butts of limestone slabs that apparently served as columns for roof support. Special attention had been given to the floors, which were sumptuous for the time.
The first building found in 1964 had a smoothed and well-fitted flagstone floor. The second one, excavated in 1970, had a true terrazzo floor of salmon-colored limestone with pairs of lines of white limestone chips, set in alignment with pilasters in the walls. The existence of the terrazzo floor - a construction technique previously thought to have been invented by the Romans about 7,000 years later - indicates an early knowledge of pyrotechnology, making cement by burning limestone and setting in the limestone and marble chips.
Since 1978, a team of architectural specialists from Karlsruhe University in West Germany has been working with the Turkish and American archaeologists.
The third building, discovered in 1984, had three small rooms in the back, two of which contained fragments of 76 human skulls, many blackened in fire.
``At this range of time, 7000 BC or soon after,'' says Braidwood, ``there was evidently a fascination with the human skull in the Levant. A small number of adult human skulls have been found at other early village sites, and the Cayonu skulls appear to be an aspect of this phenomenon. Our physical anthropologist, Dr. Metin "Ozbek, has accounted for at least 172 other individuals found outside the skull building, either in burials under house floors or between houses. So the question is, who did you have to be, what did you have to have done in your life to get your skull buried in the `skull house'?''
In addition to the human skulls, two to three full cattle skulls with horns were found last year. According to Michael Davis, a 10-year veteran of the project, this is an indication that social and religious institutions were built around the non-controlled, or hunted, source of food. Before this find, the earliest evidence of the bull's-head-and-horns motif was from 1,500 years later, when it appeared painted on early Middle Eastern pottery.
The biggest question remaining for the Joint Prehistoric Project is how to account for a village of the size and architectural complexity of Cayonu at a time when the inhabitants still had to depend on hunting for their supply of animal protein.
The archaeologists will concentrate during the coming season on exposing a large portion of the earliest phase of the village, when food production was just beginning.
They also hope to excavate the final phase of the village - developed some 500 years later - to trace the beginnings of the domestication of livestock, particularly sheep and goats, a second thrust of the agricultural revolution. ``This will be the first archaeological record of the immediate impact on human society of the introduction of livestock production,'' says Davis.