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The South American evidence points to well-adapted populations with varied subsistence patterns who occupied all major environmental zones of the continent by at least 11,000 radiocarbon years ago (13,020 calendar years) — before Clovis had spread throughout North America. The diverse regional technological traditions of the south show no relationship to Clovis.

For South America, a model of mass-population movements into already-occupied territory is not necessary. Although invasions may be more dramatic than models of a slow, indigenous population growth and adaptation, the latter seems the best fit with the known archaeological record from South America. The best explanation is an initial entry into South America well back in the Late Pleistocene — thousands of years before the Clovis culture came to the north.

To illustrate the regional diversity that was found throughout South America by the time the Clovis complex was spreading across North America, I offer a sampling of sites with dates to Clovis age or several millennia earlier, plus two sites that apparently date to very early times:

* Taima-taima: In the Caribbean coastal zone of Venezuela, this site is at a water hole among low hills. The region is now a semiarid thorn forest, and paleoenvironmental evidence suggests roughly the same setting 13,000 years ago (15,350 cal BP), when hunters, using long, thick El Jobo points shaped like willow leaves, killed and butchered a juvenile mastodon there. José Cruxent initiated archaeological research at the site.

* Tibitó: High in the Andean uplands of Colombia, the Tibitó site revealed clusters of bone fragments and stone artifacts distributed in activity areas around a large boulder. Excavated by Gonzalo Correal and associates, it is radiocarbon dated to 11,740 years ago (13,700 cal BP). Faunal remains include extinct horse, mastodon, and deer. The stone artifacts are very simple, unifacial tools showing minimal retouching.

* Pachamachay: People may have lived even higher in the Andes. The cave of Pachamachay, excavated by John Rick, is at an elevation of 4,300 meters (13,000 feet) on the high, grassy puna of central Peru. The site provided evidence of camelid hunting with triangular and lanceolate (long, narrow) points and produced a radiocarbon age of 11,800 years (13,800 cal BP).

* Quebrada Jaguay: Evidence of a specialized maritime economy is found on the desert Pacific Coast of southern Peru. The oldest site known at present — labeled QJ-280 — produced a radiocarbon date of 11,105 years ago (13,025 cal BP). The site, excavated by Dan Sandweiss and associates, indicates intensive exploitation of fish, marine clams, crustaceans, and seabirds. Most of the tools, weapons, and utensils of the earliest occupants likely were made of perishable materials, as only flaking detritus and a few broken or unfinished stone tools were found.

* Monte Verde: In the very far south, the now-famous Monte Verde site, excavated by Tom Dillehay and associates, is in the temperate rain forest of south-central Chile. By 12,500 years ago (14,850 cal BP), there was a substantial settlement here, its organic remains preserved under a peat deposit. The abundant floral and faunal remains indicate a subsistence economy built primarily on collecting a wide variety of plants over a large area, with some exotic materials brought or traded from the coastal zone and the Andes range. While a number of wood items were found, most of the stone artifacts are quite simple: naturally sharp-edged pebbles or simple flakes.

* Los Toldos and Piedra Museo: East over the Andes mountains, people had moved into the grasslands of Patagonia in southern Argentina. Augusto Cardich reported a radiocarbon date of 12,600 years (14,900 cal BP) in 1973 on the lowest occupation level at the rock shelter site of Los Toldos, with a unifacial stone industry and remains of extinct animals. Recent excavations by Laura Miotti and associates at a rock shelter in the Piedra Museo locality, not far from Los Toldos, produced a radiocarbon date of 12,890 years (15,200 cal BP) for a small assemblage of flakes and artifacts with extinct fauna.

* Lapa do Boquete: More than half a dozen archaeological sites have been radiocarbon dated to 11,000 years ago (13,020 cal BP) or earlier in the interior uplands of eastern Brazil. One example is the Lapa do Boquete, a large rock shelter excavated by André Prous and associates. The site is in a semiarid savanna-woodland with a variety of game and edible plants. Four radiocarbon dates between 12,070 and 11,000 years ago (14,000-13,020 cal BP) were obtained on charcoal from the lowest occupation level, which yielded remains of palm nuts, freshwater mussels, fish, and bones of small- to medium-sized mammals in association with an assemblage of unifacial flake tools.

* Caverna da Pedra Pintada: Foragers had also adapted to the tropical rain forest deep in the Amazon Basin. The lowest occupation level in this large rock shelter just north of the Amazon River has two radiocarbon dates of around 11,100 years ago (13,025 cal BP). The site, excavated by Anna Roosevelt and associates, suggests a foraging economy exploiting a variety of tropical fruits and nuts, stream fishing, mussel collecting, and small-game hunting.

If a variety of well-adapted, regional populations had become established in every major environmental zone of South America by the end of the last Ice Age, how early did people first arrive on the continent? Two sites suggest the initial entry may have occurred as much as 35,000 years ago.

The first is Tom Dillehay's Monte Verde site in Chile. A test pit, placed across a creek from the Monte Verde II settlement, found artifacts and features deeply buried in a sand stratum. The position of this stratum within the geological sequence in the region supports a radiocarbon age of 33,370 years on charcoal fragments from the features — lenses of clay within the sand that possibly represent hearths.

A total of 26 lithic (stone) specimens were recovered in direct association. One specimen is a basalt core with at least 11 flakes removed; close examination shows use-wear and a residue of mastodon blood. Of 20 flakes or faceted stones, six show use-wear. Further investigation is planned, but this is certainly a potential time bomb sitting under any model that maintains an initial entry of people into the Americas no earlier than 15,000 years ago.

The other South American archaeological site with comparable antiquity is the Toca do Boqueirão da Pedra Furada, a large rock shelter at the foot of a high sandstone cliff in northeast Brazil. It was excavated from 1978 to 1988 by Niéde Guidon and associates. Within the rock shelter, up to five meters (16.4 feet) of sediment have yielded approximately 600 simple stone artifacts, pebble tools and flake tools, and a long, stratified series of finite radiocarbon dates on charcoal that range back to about 32,000 years ago. Several indefinite dates from lower levels hint at an age of over 40,000 years.

Some believe the validity of Pedra Furada was buried by a critique published by several North American researchers who attended a field conference at the site in 1993, but it cannot be so easily discounted. The essential issue at Pedra Furada is whether any real stone artifacts came from the Pleistocene deposits within the shelter. Critics of the site have suggested that the specimens classified as artifacts could have been flaked naturally in a high-energy depositional environment — but no such environment existed within the sheltered area where the specimens were found, as the sediments are mainly derived from slow weathering of the sandstone overhang. I believe the site of Pedra Furada is not to be dismissed so readily.

The evidence from South America suggests the Clovis phenomenon was a regional North American development — and a rather late one at that, especially if the really early archaeological sites in Chile and Brazil prove to be valid.

For decades, North American archaeologists have discounted the South American evidence because it hasn't met their expectations or fit their models. Now it is impossible to ignore the implications: A population with a simple lithic technology entered the Americas much earlier than is generally accepted.

RUTH GRUHN, Professor Emerita at the University of Alberta, Edmonton, Canada, has pursued the first settlements of the New World throughout North and South America.

Fuente: Discovering Archaeology Magazine