DMANISI, Georgia - A small team of archaeologists had worked for years here piecing together what they could of an old medieval fortress town perched high above two rivers, but then the rhinoceros crashed the party. And that set in motion a different sort of archaeology that has now come up with the oldest human remains ever unearthed outside Africa.
Fossils and relics show that, more than 1.7 million years ago, the first intercontinental wanderers found their way here, bringing with them simple stone tools and setting themselves up by the shores of two prehistoric lakes. They may well be the ancestors of every Asian, European and Native American alive today.
They found here the abundant sunlight, water and vegetation that the southern flank of the Caucasus Mountains still provide. But the neighborhood had a different cast all the same: Where sheep, goats and pigs now graze and root for food, ostriches and giraffes once came down to the lakes, and so did saber-toothed tigers, panthers and, yes, rhinoceroses. And that was the key.
Dmanisi lies in a gentle valley, on top of a thick lava flow laid down about 100,000 years before the early humans came. Since then, the Masavera and Pinezaouri rivers have cut deep ravines into the volcanic basalt, and thousands of centuries later, this made the 300-foot high promontory above their confluence a natural place for medieval Georgians to build a fortress and trading center.
By the 9th century AD, Dmanisi was the second most important place in Georgia, which at the time was a small but proud Christian kingdom surrounded by enemies. It was abandoned in the 18th century, and, since 1936, archaeologists have been coming here trying to learn more about what life was like in those comparatively not-so-distant times.
Jumber Kopaliani, who heads the project today, gladly takes a visitor on a tour of his 32-acre domain. There's the private bathhouse for the commander of the fortress. There's the inscription over the door of the church, exempting newlyweds from taxes. There's the 5th century sarcophagus inside the church.
But he knows that the excitement is underground today. Everything began to change about 20 years ago, on the day when one of the archaeologists decided he might learn something by looking through a medieval garbage pit. Hardly more than three feet down he came upon some bones and a tooth that looked like the probable remains of a courtly feast, but he showed them to a paleontologist friend, Abesalom Vekua, who saw something altogether different: that tooth had come out of the mouth of a rhinoceros.
"Well, rhino bones in medieval times is a little strange," David Lordkipanidze, head of the paleontology department at the Georgia State Museum, said last week.
Before long the archaeologists realized that the site was full of fossils, all just below the surface. While a thousand or so years ago the knights of old were defending their verdant kingdom from barbarian marauders, while artisans fired ceramics and merchants traded with kingdoms as far away as the Rhine, practically right under their feet the ground was jam-packed with fossils from another world altogether.
In fact, the medieval residents of Dmanisi must have seen some of these fossils themselves, because they dug a number of pits six feet deep. "I don't know what they kept there," said Lordkipanidze. "Water? Wine? Slaves?" But even today, fossil fragments are easily visible in the dirt walls of these pits.
After the rhino tooth was found, interest quickened when, in 1984, a medievalist spotted some prehistoric stone tools and realized what they were. This was the first sign of a human presence. A human jaw was found in 1991, and a metatarsal - one of the bones in the foot - was unearthed in 1995, but the dating and identity of these fossils was challenged by some paleontologists.
Last summer, though, the ambiguity vanished when heavy rains revealed two skull fragments at a site being excavated by a team that now included both Georgian and German scientists. Three different methods were used to date the finds - by examining the magnetic polarization of the underlying basalt, measuring the decay of potassium-40, and using a technique called "argon-argon dating," which was performed by the Berkeley Geochronology Center in California.
The results were reported at a conference in France two months ago, and in Science magazine in May, and have been widely hailed as a spectacular discovery. The fossils are at least 500,000 years older than any found before in Europe. Asian finds are closer in age, but less definitively dated.
The paleoanthropologists led by Lordkipanidze have classified the remains as those of an early hominid called Homo ergaster, a species that lived in Africa between 1.9 million and 1.4 million years ago. The cranial capacity of the skull fragments is about half that of a modern human.
But these hominids were long-limbed and knew how to make stone tools. They were also meat-eaters, probably the first serious carnivores in human evolution - and the search for more abundant game may have been what propelled them out of Africa in the first place.
Near where the human fossils were found, the archaeologists also have turned up an unusually large number of bones of large predatory animals. Whether the people hunted down the animals and dragged them to this spot, or vice versa, isn't clear.
The vegetation here was similar to what the immigrants (or more likely their forebears) had left behind at Olduvai Gorge in Kenya, where Homo ergaster originated - essentially, a savanna. The Caucasus Mountains offered protection from the harsher climate to the north. The Black and Caspian seas, which were somewhat closer then, moderated the weather.
"It was very pleasant here," said Vekua, the man who identified that rhinoceros tooth. "They had water, food, materials for weapons and tools. Everything they needed."
The fossils were found at the edge of what had been a small basin. A thin layer of sediment separated them from the volcanic basalt below. Lordkipanidze speculates that they were covered with mud in one quick stroke, probably in a flood of some kind. After that, a top layer of sediment was baked into a hard crust - warmed, perhaps, by a nearby volcano.
"And this crust is our friend," said Lordkipanidze. "It protected everything."
As the rivers on either side cut deeper into the earth, the lakes were drained and the site was left high and dry. Only about three feet of additional soil has collected on top of the crust. The result is that in one thin layer, easily accessible, lie thousands of prehistoric fossils.
Lordkipanidze, an energetic scientist with a quick smile and close-cropped gray hair, scrambles all over his site. Poppies grow in the 12-foot-square quadrant where all the human fossils have been found so far. He's delighted by the thought of several acres still to come.
And he has great plans. Europeans have been particularly excited by news of the discovery of the "first Europeans" - though there is some dispute as to whether Georgia is actually in Europe or Asia. It's also abundantly clear, he believes, that there have been several tides of migration out of Africa since the emergence of Homo ergaster, so that even if the Dmanisi hominids are in fact among the ancestors of all Europeans and Asians, they represent just one branch of the genealogical tree. Plenty of additional and more recent roots go back to Africa.
Nonetheless, the world is paying attention, and Lordkipanidze sees this as a golden opportunity to attract research funds and tourists to Georgia and to invigorate the sciences at home.
This is, of course, a terribly poor country, as are all the former Soviet republics. The State Museum in Tbilisi is a grim, dusty pile of a building, where the lights are turned off even when the electricity is on, which is haphazard at best. There has been no way to attract bright students to a field that pays nothing.
But out here in Dmanisi, where wildflowers bob and weave in the mountain breezes, anything seems possible. A campsite here, a decent house for visiting archaeologists, with running water instead of a pit outhouse, over there. A new road to Tbilisi, so the 50-mile drive doesn't have to take almost two hours.
What he envisions is a chance for Georgians to visit their national heritage, and for people from all over to visit their prehistoric one - on the same site.
Down below, where the road follows the river, an ancient pickup chugs over the potholes, its fenders and running boards reduced to a fine filigree by rust. Behind it come an elderly couple in a donkey cart, their dog trotting alertly alongside. Piglets snuffle on the verges. Over toward the village of Bolnisi, where the descendants of 18th century German immigrants lived until Stalin had them sent into exile in Central Asia, shepherds on horseback crack their whips at errant sheep.
But the timelessness is a mirage. Even Homo ergaster knew that. You can't stay in one place forever. You've got to move on.