Dentalium (genus)
Dentalium is a large genus of tooth shells or tusk shells, marine scaphopod molluscs in the family Dentaliidae. The genus contains 50 described species and about 50 extinct species. Etymology. The scientific name of this genus comes from the Latin word "dentis", meaning "tooth", based on the tooth or tusk-shaped form of these molluscs. Description. The mantle of "Dentalium" species is entirely within the shell. The foot extends from the larger end of the shell, and is used to burrow through the substrate. They position their head down in the substrate, with the apical end of the  shell (at the rear of the animal's body) projecting up into the water. These molluscs live on seafloor sediment, feeding on microscopic organisms, detritus and foraminiferans. The shells are conical and curved in a planispiral way, and they are usually whitish in color. Because of these characteristics, the shell somewhat resembles a miniature elephant's tusk. They are hollow and open at both ends; the opening at the larger end is the main or anterior aperture of the shell. The smaller opening is known as the apical aperture. Human use. South Asia. At Mehrgarh, a village located at the  foot of the Bolan Pass in Balochistan in modern-day Pakistan, ornaments made of Dentalium shell have been found at burial sites dating back to 6000 BCE. Excavations conducted by Jean-François Jarrige have described 'Exceptional grave deposits of Dentalium headbands found on the heads of several females...In Burial 274, the headband was made of woven rows of small dentalium and closed by two straps used as a clasp'. Native Americans. The shells of "Dentalium neohexagonum" have been used by Indigenous people of the Pacific Northwest and West Coast as a form of status and currency since time immemorial . The Chumash people have also been reported using dentalium as early as circa 1000 AD, in the Morro Bay area. New Zealand. Māori traditionally used Dentalium shells for decorative purposes, such as rings and necklaces. Most artefacts have been found around the Coromandel Peninsula, and typically earlier artefacts during the Archaic Period (1300–1500) are "Dentalium solidum", while later shells are "Dentalium nanum". 18th-century European use. In pre-modern medicine, these shells were considered an excellent alkali, and apothecaries would pulverize them for use in several preparations. The shell used for this purpose was described by Joseph Pitton de Tournefort  in London in the 18th century as being "of a tubular, or conical form, about 3 inches long; of a shining, greenish white; hollow; light, and divided lengthwise by parallel lines, running from top to bottom. It is about the thickness of a feather, and bears some resemblance to a canine tooth." However, it was considered at that time to be very rare, and in lieu of that, another shell was usually substituted. This was described as a multi-colored shell found in the sand where the tide had fallen; this shell was not channeled, or fluted. The large green  shell to which the writer first refers must have been either "Dentalium elephantinum" or "Dentalium aprinum", both of which are large and greenish, and live in the Indo-Pacific zone. The other shell was presumably another species, possibly "Dentalium entale", which is native to Great Britain. Species. Species within the genus "Dentalium" include: Extinct species. Extinct species within the genus "Dentalium" include: Fossils in the genus "Dentalium" are geographically widespread. This genus is very ancient, going back up to the Silurian period (age range: from 422.9 to 0.0 million years ago). It is especially represented in Cretaceous, Eocene and Miocene  fossils.