Lea este ensayo en español: El uso de los caparazones de moluscos en América antes del siglo XVI
The calcareous shells produced by organisms classified as mollusks (including snails, clams, octopuses, squids, and chitons, among others) have fascinated humans in nearly all places and times. Beyond the nutritional value of these creatures, mollusk shells were employed in antiquity for other purposes—in some cases, to make tools, but more often, to produce objects for personal adornment and religious activity. Peoples living near oceans, lakes, and rivers naturally would have utilized such proximate resources, but remarkably, certain species were sought and captured—sometimes with great difficulty—and then transported considerable distances to inland sites. There, with rudimentary technology and a significant investment of time and labor, their shells were transformed into prized objects. Such efforts suggest the great value conferred upon these shells and the central role they played in religion, where they synthesized meanings within the belief systems of several cultures that developed in the Americas prior to European contact, particularly in the Andean region, the Isthmo-Colombian area, and Mesoamerica. For example, these cultures linked mollusk shells to water, rain, and fertility, and used them to create images of important divinities, such as the Maya maize god , and their attributes, as in the case of the ehecacozcatl, the characteristic pectoral of the central Mexican god Quetzalcoatl, the Feathered Serpent .
The use of materials thought to be precious is a phenomenon that occurs alongside social differentiation and the rise of elites who require means to convey their elevated status. As societies become more complex, they generate a range of specialists to satisfy their various needs. For example, groups of people dedicated themselves to capturing mollusk species considered desirable for their size, shape, color, or iridescence. Generally, shells found dead along the shore have lost many of these attributes, as they may be broken and discolored from erosion and exposure to sunlight. Thus, the best way to obtain suitable specimens is to collect the mollusks while they are still alive. Some species can easily be obtained in shallow waters at low tide, while others require diving to great depths—a difficult activity without the aid of modern equipment. Some of the most prized shells in the Andean region, the Isthmo-Colombian area, and Mesoamerica were the brightly colored valves of the Spondylus genus, especially the crassisquama and limbatus species desired for their reddish and purple tones respectively ; . The Valdivia, Chorrera, and Cupisnique cultures were among the earliest in the Andean region to use mollusk shell ornaments, while the oldest such examples found in Mesoamerica have been dated to the Early Preclassic period (1350–1250 BCE).
Mollusk species have fairly precise habitats determined by environmental factors such as water temperature and salinity. It has been possible to identify stretches of coastline where certain species are able to live, called malacological provinces. The three cultural regions discussed here included three of these provinces: the Panamic, extending along the Pacific coast from the Gulf of California to northern Peru; the Peruvian, continuing southward from the Panamic province to central Chile; and the Caribbean, running along the Atlantic coast from the Gulf of Mexico to northern Brazil and the Antilles. While accurate species identification makes it possible to pinpoint the originating malacological province of archaeological materials, it is difficult to determine how shells arrived at their inland destinations. This is generally accomplished by finding evidence of cultural contact between regions or sites, such as the use of certain materials, the distribution of specific decorative motifs, or the diffusion of particular technologies.
Andean societies notably made use of several Panamic species, even though most of their coastline corresponds to the Peruvian province. As for the routes shells traveled from their place of origin, two hypotheses have been proposed, one based on ethnohistoric information, and the other on archaeological data. The first suggests that mullu—the Quechua name for valves of the Spondylus genus—were obtained on the Ecuadorian coast in exchange for copper axes. From there they were taken by sea to the port of Chincha on the central coast of Peru and subsequently brought via overland routes to Cusco and other Inca sites. The second hypothesis calls the first into question, citing the difficulty involved in navigating from north to south against the Humboldt Current, which was challenging even for Spanish vessels. Rather, the discovery of Spondylus and other tropical shell elements in several tambos (state-run waystations) along the roads linking Tumbes, Peru to the central Andes suggests that this trade was conducted by land. This route likely was in operation by the Early Intermediate period (200 BCE–700 CE) and used continuously through the Late Horizon (1470–1532).
It has also been proposed that the demand for Spondylus shells in the Andean region prompted contact with the Isthmo-Colombian area and Mesoamerica. According to this hypothesis, interest in this resource led to overexploitation that resulted in mullu extinction on the coast of Peru and Ecuador, forcing traders northward until they reached western Mexico. This would explain the diffusion of certain Andean cultural traits, such as metallurgy, to Mesoamerica and the latter area’s esteem for Spondylus shells .
It is generally thought that the trade routes that brought shells to inland Mesoamerican sites followed the course of rivers. We know that sites conquered by the Mexica Empire (1325–1521) on the Atlantic and Pacific coasts were obligated to pay tribute in seashells. Likewise, archaeological findings in the sacred precinct of Tenochtitlan, the capital of the Mexica Empire, indicate that some species reached the imperial metropole through the long-distance trade carried out by the pochteca (merchants who specialized in the exchange of luxury goods).
The artistic quality achieved by pre-Hispanic shell workers in the Americas is extraordinary, especially considering they mainly employed stone tools and a percussion technique that generated considerable waste before performing various masterful cuts, perforations, fretwork, and incised designs ; ; . Although mollusk shells were also used to make utilitarian objects such as musical instruments—for example, conch-shell trumpets —and containers for other materials , most of the time they were employed in the production of ornamental pieces such as beads, which could be strung and worn on the body or incorporated into various types of garments along with other materials such as cotton, camelid hair, and metals ; . Shell inlays were applied to other materials and worked into mosaics ; ; ; . Other shell ornaments include pendants , earpieces, bracelets ; , and rings.