As it happens, the Archaic Period, approximately 7,000 to 5,000 years ago, is the least known archaeologically in Costa Rica. This is in contrast to Central Panama, where Archaic sites are well known and have been excavated by the dozens. There, archaeologists Richard Cooke of the Smithsonian Tropical Research Institute and Anthony Ranere of Temple University have worked extensively on Archaic sites and have carried out research and classification of chipped stone tools characteristic of the period, which they have appropriately designated as the Tropical Archaic. This is because the stone tools (points, scrapers, grinding stones and others) are rather different in form and structure as compared to contemporary stone artifacts in North America and the Andean Area.
Very few Tropical Archaic period sites are known in Costa Rica, principally due to their scarcity and short-lived nature, their small size, and the profuse tropical vegetation and pastures that cover most of the country, obscuring such sites and making their secure identification very difficult. There are no Carbon-14 dates as yet for this period. Instead, the few sites that are known to date have been identified through the forms and techniques used in making chipped stone tools such as projectile points, scrapers, and the size and shape of tiny sharp flakes of flint-like stone that were embedded in a wooden based and used to grate tubers of cassava and other root crops.
Also, the chipping techniques that were used during Tropical Archaic times were less skilled and sophisticated than those of the older Paleoindian Period (see Costa Rica 10,000 years ago INCLUDE LINK HERE), recognizably so. The Paleoindian site described in the article noted, called Turrialba (discovered and published by the author in 1977 and 1979), was a rare and fortuitous find, because indigenous peoples actually worked on their chipped stone tools there over many centuries, as the almost glass-like stone source was located in a creek bed adjacent to the site. It is located on old bluffs overlooking the Reventazon River and one of its tributaries, whoere the large animals of the time came to drink, and thus were easier prey.
The Tropical Archaic Period represents a kind of gradual transition from the Paleoindian, and an eventual change to settlements occupied for a longer time (though by no means permanent). Hunting continued as a very important activity, but the giant animals of the late Pleistocene were extinct, so hunting tools and tactics had to be changed.
When bare ground is exposed, with scarce periodic rainfall, prehistoric chipped stone tools and debris are much more easily discerned. Central Panama has such conditions, and numerous Tropical Archaic sites and artifact types have been known and studied there for many years. Comparisons with data from Panama can help to identify such sites in Costa Rica, though only to a certain degree, as the climatic differences and likely different styles of human occupation and adaptation to them, resulted in different types of chipped stone tools. During the tropical Archaic Period, no functional ceramics were yet produced; thus, like the Paleoindian Period, the Tropical Archaic is designated as preceramic.
As was the case in Paleoindian times, migratory bands of only some two dozen people, who followed the growth and harvest cycles of fruit and seed-bearing trees, bushes and grasses, the Tropical Archaic peoples were egalitarian everyone equal at birth although special talents such as prowess in hunting, tool-making, and perhaps the first diplomats who were skillful at initiating and maintaining trade/exchange relations with other groups, probably brought greater status to some individuals. These inter-group contacts must also have resulted in a more rapid dissemination of technology and ideas.
The most significant development during the Archaic period in the Americas in general was the first appearance of agriculture, which gradually resulted in genetic changes in wild plants through domestication processes that benefited the human population and spurred its more rapid growth. Agriculture developed earlier in some other areas, such as the dry northeastern region of Mexico, and especially in the Neolithic period in the Middle East (specifically the famous fertile crescent defined by the Tigris and Euphrates rivers), where the first evidence of agriculture was dated to around 9,000 years ago. Yet agriculture was invented and spread rapidly during roughly the same time span throughout most of the world.
There are many hypotheses as to how agriculture began and why larger numbers of people started to live in the same place for longer periods of time. This is what archaeologists call a more sedentary settlement pattern. In the Tropical Archaic, sites become more sedentary, but they were still very small groupings, thus the difficulty in identifying them.
A perhaps overly simplistic hypothesis for the origin of agriculture (thought not discarded) is that people started to notice some of the edible seeds and grasses they brought to their camps were sprouting anew in their refuse dumps. To propagate this phenomenon would mean much less trekking and seasonal migrations, and less longer-range hauling of foodstuffs back to their domiciles.
But I think it is more likely that the growing populations simply began to congregate in the most promising environmental niches, where most of the essentials for life were relatively concentrated. This scenario probably played out first in harsher environments such as desert-like, dry lands, where the beneficial niches were not plentiful, as in the Mexican and Middle Eastern examples noted above. Agriculture arose somewhat later in the humid tropics like Costa Rica.
In my excavation projects in Costa Rica, mostly in the Central Atlantic Watershed and the Central Valley, maize is the domesticated field crop most often found (in carbonized tiny ears and grains, which are much more chemically stable and do not disintegrate as readily as other non-carbonized organic matter). Manioc or cassava (yuca in Spanish), a tuber crop high in carbohydrates, may have been cultivated even earlier, but no concrete evidence has been found to date.
These crops and others, such as beans and nuts, require equipment for grinding and mashing, and in the Tropical Archaic we see the first crude grinding tables or metates and mullers or manos, made from river cobbles of volcanic rock. These are the first examples of pecked and ground stone artifacts in the archaeological record, not being present in the Paleoindian Period, and they are sure telltale signs of the existence of agricultural practices.
Grooved and Polished Stone Axes (Celts)
Ground and polished axes of fine-grained hard stone, usually in the shape of petals or teardrops, constitute another diagnostic artifact type that appears for the first time in the late Archaic Period. Such axes, in various sizes, continue throughout the entire Costa Rican archaeological sequence, but the Archaic examples are the oldest, the first such tools known, and they are distinguished by a wide, deep groove near the poll, the end of the axes that was hafted to a strong wooden handle for more leverage and force; these tools were also known as celts. All the ground and polished stone axes made after the Archaic Period were also hafted, but the large grooved version never appeared again.
The polished axes in all periods were wood-splitting and tree-felling tools. The working edge is tapered and thin, although not sharp like modern metal axes. This is because it was used more as a wedge, thus the much thicker body of the tool and its smooth surface. It was used for roughing out large wooden objects, such as canoes, by being driven in and letting the larger, hard mid-section of the tool open and split the wood.
Trees were felled by the same process, laborious to be sure but the real question is: Why were they cut down? Some large wooden objects were probably made from the felled trees, but, along with the metates and manos, these kinds of axes are indirect evidence of the clearing of land for agriculture, a hugely important landmark a quantum jump in technology and human cultural evolution around the world.
