Spondylus: The Precolumbian Use of the Thorny Oyster

Prehistoric Uses of The Thorny Oyster

Spondylus princeps (Spiny Oyster)
Spondylus princeps (Spiny Oyster). Kevin Walsh

Spondylus, otherwise known as the "thorny oyster" or "spiny oyster", is a bivalve mollusc found in the warm waters of most of the oceans of the world. The Spondylus genus has about 76 species living worldwide, three of which are of interest to archaeologists. Two spondylus species from the Pacific Ocean (Spondylus princeps and S. calcifer) held important ceremonial and ritual significance to many of the prehistoric cultures of South America.

S. gaederopus, native to the Mediterranean Sea, played an important role in the trade networks of the European Neolithic. This article summarizes information about both regions.

American Thorny Oysters

S. calcifer's shell is red and white variegated, with a reddish-purple band along the inner margin. This mollusc lives in large concentrations at fairly shallow depths from the Gulf of California to Ecuador. S. princeps is solid coral red, and it is found as single shells or in small groups at depths up to 50 meters below sea level. It is found from Panama to north-western Peru. The Quechua word for Spondylus is "mullu" or "muyu".

Spondylus shell first appears in Andean archaeological sites dated to the Preceramic Period V [4200-2500 BC], and the shellfish was consistently used up until the Spanish conquest in the 16th century. Andean people used Spondylus shell ritually as complete shells, cut the shell into pieces and used them as inlay or jewelry, and even ground the shell into powder and used it as architectural decoration.

Its form was carved into stone and made into pottery effigies; it was worked into body adornments and placed in burials.

Spondylus is associated with water shrines in the Wari and Inca empires, at sites such as Marcahuamachucot, Viracochapampa, Pachacamac, Pikillacta and Cerro Amaru. At Marcahuamachucot was recovered an offering of about 10 kilograms (22 pounds) of Spondylus shells and shell fragments, and small turquoise figurines carved in the shape of Spondylus.

Diving for Spondylus

Spondylus lives up to 50 meters (165 feet) below sea level, and retrieving them requires experienced divers. The earliest known representations of spondylus divers in South America comes from the Early Intermediate Period [~200 BC-AD 600]: they likely represent S. calcifer and the images probably represent diving off the coast of Ecuador. The numbers of shells found on Andean archaeological sites suggests that the shells were traded from Mesoamerica during prehistoric and historic times.

Exports of shells from the coasts presumably moved inland via llama caravans as illustrated on Moche pottery.

The Food of the Gods?

Spondylus was known as the "Food of the Gods", according to a Quechua myth recorded in the 17th century. Some debate exists among scholars as to whether this means that the gods consumed Spondylus shells, or the flesh of the animal. Glowacki (2005) makes an interesting argument that the effects of eating spondylus shellmeat out of season may have made them a part of religious ceremonies.

Between the months of April and September, the flesh of Spondylus is toxic to humans, a seasonal toxicity recognized in most shell fish called Paralytic Shellfish Poisoning (PSP).

PSP is caused by toxic algae or dinoflagellates consumed by shellfish during those months, and typically it is at its most toxic following the appearance of the algae bloom known as the "red tide". Red tides are associated with El Nino oscillations, themselves associated with catastrophic storms.

The symptoms of PSP include sensory distortions, euphoria, loss of muscular control and paralysis and death in the most severe cases. Glowacki suggests that purposefully eating Spondylus during the "wrong" months may well have effected a hallucinogenic experience associated with shamanism, alternative to other forms of hallucinogens such as cocaine.

Spondylus gaederopus lives in the eastern Mediterranean, at depths between 6-30 m (20-100 ft). Spondylus shells were prestige goods showing up in burials within the Carpathian basin by the Early Neolithic period (6000-5500 cal BC). They were used as whole shells or cut into pieces for ornaments, and they are found in graves and hoards associated with both sexes. At the Serbian site of Vinca in the middle Danube valley, Spondylus and Glycymeris were both found in contexts dated to 5500-4300 BC, as a part of the trade network from the Mediterranean region.

By the Middle to Late Neolithic, the number and size of Spondylus shell pieces had sharply dropped off, found only as tiny pieces of inlay in necklaces, belts, bracelets and anklets. In addition, limestone beads appear as imitations, suggesting to scholars that the sources of Spondylus dried up but the symbolic importance of the shell had not.

Oxygen isotope analysis supports scholars' contentions that the sole source of the central European Spondylus was the Mediterranean, specifically the Aegean and/or Adriatic coasts. Shell workshops were recently identified the late Neolithic site of Dimini in Thessaly, where over 250 worked Spondylus shell fragments were recorded. Finished objects were found in other locations throughout the settlement, but Halstead (2003) argues that the distribution suggests that the amount of production waste indicates that the artifacts were being produced for trade into central Europe.


This article is a part of the About.com guide to the Raw Materials, and the Dictionary of Archaeology.

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