On the north central coast, the stretch between the Casma and Huarmey rivers was heavily populated. One site, at Culebras, was a large village on a terraced hillside, with semi-subterranean houses whose underground parts were lined with basalt blocks and whose upper parts were built of lighter materials such as adobe blocks. They originally had hard clay floors, and some had guinea-pig hutches consisting of stone-lined tunnels connecting two rooms at floor level. The guinea pig, normally vegetarian, appears to have been taught to feed on small fish. A site at Huarmey has provided the earliest known instance of corn on the coast, and it also occurred in the top Preceramic levels at Culebras.
Burials at Culebras were tightly flexed, wrapped in twined mats and cotton cloth, and accompanied by gourd vessels and beads and pendants of stone, shell, or bone. The skulls of these people were deformed by having been bound to cradleboards in infancy. There was a cemetery, but many burials were under house floors. No ceremonial buildings are known in this area.
Farther north, at the mouth of the Chicama River, is Huaca Prieta, which was the first Preceramic site to be excavated. A thick midden, it contains some subterranean houses lined with cobblestones and roofed with earth supported by whalebones and wooden beams. The twined textiles found there were the vehicle for a peculiar art style, showing highly stylized crabs, double-headed snakes, birds, and human beings, expressed by warp manipulation designed to bring groups of warps of one colour to one face. The dyes have faded, and the only way to recover the designs is by examination under a microscope. Such textiles were not confined to this area, but they have been more fully studied there. Woven textiles were rare, and weaving was combined with twining in a way that shows that a loom was not used.
Unlike the area farther north, sites along the central coast had ceremonial buildings, of which the most remarkable is El Paraíso in the Chillón Valley. This is an imposing stone-built structure on an artificial mound, with a central stairway leading up to a group of rectangular rooms. The central block, which occupied a commanding position in a side valley, has been partly reconstructed, but there were extensive wings that may have been residential, though they now appear as little more than piles of stones. Floodwater farming may have been practiced there, but definite signs of it have been obliterated by modern cultivation. At Río Seco, a few miles to the north, are two pyramids, constructed by filling a group of preexisting rooms with boulders, building adobe-walled rooms on top of them, and finally filling these up also.
Apart from one site, Kotosh, near modern Huánuco in the central Andes, little is known of the highland final Preceramic. A Japanese research team has found structures of undressed stone chosen to present flat wall surfaces, set in mud, covering an area of at least 200 by 100 yards (180 by 90 metres), in some parts of which was a succession of buildings piled up to a considerable height. Among these were two superimposed temples, the lower being a rectangular structure on a stepped platform about 26 feet high. The floor was surrounded by a broad, low bench, and each outside wall had two or three rectangular niches. The walls and floor were covered with two coats of mud plaster, and beneath the central niche at one end was a pair of crossed forearms modeled in the same material. This temple was later buried in boulders surrounded by a retaining wall and covered by a new floor on which a second temple was built, of which little remains. The burial of the first temple to act as a raised foundation for the second recalls the construction at Río Seco. The Initial Period
The next epoch, called the Initial Period by the American scholar John H. Rowe, and the Lower Formative by the Peruvian archaeologist Luis G. Lumbreras, began with the introduction of pottery. The earliest ceramics have yielded radiocarbon dates of about 1800 bc, although Rowe has suggested that even a date of 2100 bc is plausible. Ceramics from this period have been found on the central coast between Las Haldas, in the Casma-Huarmey region, and Lima. These are considerably later than the earliest pottery finds at Puerto Hormiga on the northern coast of Colombia near Panama (before 3000 bc) and Valdivia in Ecuador (c. 2700 bc). The period ends with the spread of the Chavín cult (also called the Early Horizon; see below).
Lumbreras has stressed agriculture as a more telling indicator: while no single starting date has been cited for this achievement, beans may have been cultivated for centuries if not millennia before the date of the earliest pottery. Bottle gourds and squashes were other cultivated species. Potatoes and other tubers, so important in later times, did not keep well in highland circumstances; but some researchers believe that Andean peoples were reliant on wild tubers and rhizomes 10,000 years ago, although these groups had not yet domesticated them. It has been demonstrated that on the coast virtually all the crops that were important in 1532 (with the notable exception of corn) were already known and in daily use during the Initial Period.
The introduction of pottery at first made little difference to the general pattern of life; cooking continued to be done by roasting on hot stones. On the coast, there was a gradual increase in the consumption of cultivated plants, grown mainly in the lower reaches of the valleys; but the basic reliance on seafood continued. An important innovation was the development, or possibly the introduction, of the heddle loom, but, if it was introduced, its origin is not known. At first it seems only to have been used for making plain-weave cotton cloth. Village life and temple buildings spread over the country, except to the far south, where conditions favoured the continuance of hunting and gathering. Corn spread from the centre over most of the coast, and cassava, or manioc (an edible root), and peanuts (groundnuts) appeared there for the first time, their ultimate source being the Amazonian lowlands.
New ceremonial centres showed considerable diversity. Examples include La Florida, a huge pyramid in Lima that formed the nucleus of a yet-unmapped building complex. The Tank site at Ancón consists of a series of stone-faced platforms on a hill. Las Haldas has a platform and three plazas; two smaller similar sites are also known. The old centres at El Paraíso and Río Seco had been abandoned, but, in the highlands, Kotosh continued to be occupied. Any constructions at Yarinacocha in a wet, stoneless area would have been of wood or other perishable materials.
The variety of the pottery suggests that it was derived from several different sources. In the Lima area, the earliest examples are neckless jars and incurved bowls with thickened rims and rounded bottoms, very uneven in shape. Some later types are pebble polished and the jars thinner. Other later types include bottles with straight spouts, which may have simple incised or applied decoration, and open bowls. Finally, as the period drew to a close, tan-coloured decorated wares, with punctate or red-painted areas outlined by incised lines, as well as orange ware with black stripes, were produced. A type found on the south coast is a small, double-spouted bottle with simple negative-painted decoration, the first appearance of a form long-lived in that area and of a decorative technique that later spread widely over the country.
In the highlands, the earliest pottery at Kotosh consists predominantly of simple bowls with somewhat constricted mouths, and bowls with gently rounded bases meeting the vertical to outsloping concave walls at a sharp angle. There are rare double-spout-and-bridge bottles, closed vessels with two tubular spouts connected by a solid bridge. The ware is mainly dark gray, black, or dark brown to sombre red, and it may have a red slip. The decoration—which was either applied to a broad zone covering most of the walls or, on the neckless jars, formed a ring around the mouth—consists of linear incision, hatching, stamped circles, punctation, or excision. Postfired painting in red, yellow, and white frequently covers excised, hatched, and stamped areas. Despite the fact that Kotosh was on the eastern side of the Andean watershed, its pottery had little in common with that of Yarinacocha, save some similar decorations and the double-spout-and-bridge bottle.