Spondylus

Thorny oysters
Temporal range: Mesozoic–Present
A shell of S. regius
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Pectinoida
Suborder: Pectinina
Superfamily: Pectinoidea
Family: Spondylidae
Gray, 1826
Genus: Spondylus
Linnaeus, 1758
Species

See text

Spondylus is a genus of bivalve molluscs, the only genus in the family Spondylidae. As well as being the systematic or scientific name, Spondylus is also the most often used common name for these animals, though they are also known as thorny oysters, spiny oysters, and as spondylids. The meat of these bivalves is edible.

The many species of Spondylus vary considerably in appearance and range. They are grouped in the same superfamily as the scallops. They are not closely related to true oysters (family Ostreidae), however they do cement themselves to rocks, rather than attach themselves by a byssus. Their key characteristic is the two parts of their shells are hinged together with a ball-and-socket type of hinge, rather than a toothed hinge as is more common in other bivalves. They also still retain vestigial anterior and posterior auricles ("ears", triangular shell flaps) along the hinge line.

Liks scallops, Spondylus spp. have multiple eyes around the edges of their shells, and have relatively well-developed nervous systems. Their nervous ganglia are concentrated in the visceral region, with recognisable optic lobes connected to the eyes.

Spondylus shells are much sought after by collectors, and a lively commercial market exists in them.

History

The genus Spondylus originated in the Mesozoic era and can be found in fossil forms in Cretaceous rocks in the Fort Worth Formation of Texas and in the Trent River Formation of Vancouver, as well as other parts of North America.[1][2]

Archaeological evidence shows people in Neolithic Europe were trading the shells of S. gaederopus to make bangles and other ornaments as early as 4500 BC (Varna Necropolis). The shells were harvested from the Aegean Sea, but were transported far into the centre of the continent. In the LBK and Lengyel cultures, Spondylus shells from the Aegean Sea were worked into bracelets and belt buckles.

S. princeps is found off the coast of Ecuador, and has been important to Andean peoples since pre-Columbian times, serving as offerings to the Pachamama, as well as some kind of currency.[3] In fact, much like in Europe, the Spondylus shells also reached far and wide, as pre-Hispanic Ecuadorian peoples traded them with peoples as far north as present-day Mexico and as far south as the central Andes.[4] The Moche people of ancient Peru worshipped animals and the sea, and often depicted Spondylus shells in their art.[5]

Species

Pacific thorny oyster, S. crassisquama Lamark, 1819, from the Sea of Cortez, Mexico
The interior of two fossil valves of Spondylus from the Pliocene of Cyprus
Cat's tongue oyster, Spondylus linguaefelis Sowerby, 1847, from Hawaii
A view of the colorful mantle edges of a live thorny oyster from East Timor: The eyes can be seen on the fringe between the mantle and the shell.

References

  1. ↑ Finsley, Chalres. 1999. A Field Guide to the Fossils of Texas. Gulf Publishing. Lanham, Maryland. plate 55.
  2. ↑ Ludvigsen, Rolf & Beard, Graham. 1997. West Coast Fossils: A Guide to the Ancient Life of Vancouver Island. pg. 104
  3. ↑ Carter, Benjamin. "Spondylus in South American Prehistory" In Spondylus in Prehistory: New Data and Approaches. Ed. Fotis Ifantidis and Marianna Nikolaidou. BAR International Series 2216. Oxford: Archaeopress, 2011: 63-89.
  4. ↑ Shimada, Izumi. “Evolution of Andean Diversity: Regional Formations (500 B.C.E-C.E. 600). The Cambridge History of the Native People of the Americas. Vol. III, pt. 1. Ed. Frank Salomon & Stuart B. Schwartz. Cambridge: Cambridge University Press, 1999: 350-517, esp. "Mesoamerican-Northwest South American Connections", pp. 430-436.
  5. ↑ Berrin, Katherine & Larco Museum. The Spirit of Ancient Peru:Treasures from the Museo Arqueológico Rafael Larco Herrera. New York: Thames and Hudson, 1997.

External links

A fossil Spondylus gaederopus from the Pliocene of Cyprus

Bibliography