Amazing Shells of the Academy of Natural Sciences of Drexel University

Academy of Natural Sciences of Drexel University

This exhibition features highlights of the Academy's Malacology Collection, the oldest shell collection in the U.S. 

10 Million Shells and Counting
The Malacology Collection at the Academy of Natural Sciences of Drexel University in Philadelphia dates back to the institution’s founding in 1812, when one of its founders donated a box of shells and madrepores (reef-building corals). Since then, the shell collection has grown considerably and now occupies more than 250 cabinets containing more than 13,000 drawers and 10 million specimens, together weighing more than 55 tons. The collection represents every region of the world and is a priceless resource for scientists in many disciplines. It is fully searchable online through the Academy’s website,, and more than 5,000 of the most scientifically important specimens can be viewed as high-definition images on any web browser.
Map Cowrie, Leporicypraea mappa
This relatively common species lives in shallow water on coral reefs in the western Pacific and Indian Oceans. The wavy band shows where the two sides of the animal’s body meet when it envelops the glossy shell, hiding it completely. The pale patches in the pattern mark the position of the animal’s numerous tentacle-like papillae when it is fully extended.
Horned Helmet Shell, Cassis cornuta
This large species lives on sand in shallow water in the Red Sea and throughout the Indian and western Pacific Oceans. It grows in regular increments, with each new section a larger version of the previous one; the large horns do not fully develop until the final stage. Adults can live for many years, their shells gradually eroding and acting as a home to sponges, corals, boring bivalves and other marine organisms.
Heart Cockle, Corculum roseum
This small but attractive species displays an impressive range of colors and patterns. It is common in the Indo-Pacific region, where it lives in shallow sand areas around coral reefs. Its common name derives from its shape, and it is distantly related to the common cockles of northern oceans.
Pilsbry’s Spider Conch, Lambis pilsbryi
This dramatic shell was named by R. Tucker Abbott, the third chairman of the Malacology Department at the Academy of Natural Sciences, for his predecessor Henry A. Pilsbry. It is known exclusively from the Marquesas Islands in the Indian Ocean, where it lives on sand in shallow water.
Regal Murex, Hexaplex regius
Native to the Pacific coasts of the Americas from Baja California to Peru, this marine species is a carnivore that preys on other invertebrates. Its shape and coloration can vary somewhat, but it always features some pink and black over a basic white shell.
Venus Comb Shell, Murex pecten
This shallow-water marine species demonstrates the sense of building a shell that is as large and hard to bite as possible. The animal creates the spines by forming its flesh into long, narrow tubes and filling them in with shell material. It was first scientifically named in the auction catalog of the collection of the Duchess of Portland in 1786, though it was known in China and Japan as “fish-bone shell” long before that.
Magnificent Scallop, Nodipecten magnificus
This large scallop is endemic to the Galapagos Islands and part of Ecuador. Its size and deep scarlet color have made it a favorite among collectors since the early nineteenth century, but like all Galapagos species it is now protected.
Argonaut, Argonauta argo
This shell is also called the Paper Nautilus, but the animal that makes it is actually an octopus that lives in the open ocean. The shell is only made by females, and its function is to protect the animal’s eggs until they hatch. The light but surprisingly rigid shells are sometimes cast up on beaches after storms and can be found in almost all parts of the world. There are several species, of which Argonauta argo is the largest.
Fuzzy Nautilus, Allonautilus scrobiculatus
Though closely resembling its better-known cousin the Pearly Nautilus, this species differs by having visible early coils and a thick, velvet-like protective coating (the periostracum) on the living shell. When the coating is removed, as here, a pattern is revealed that is similar to that of other Nautilus species. It is native to the deep seas surrounding New Guinea and is comparatively rare.
Atlantic Thorny Oyster, Spondylus americanus
This marine species is highly variable in color and the length and shape of its spines. It lives permanently attached to hard objects like rocks or piers, and in life it is covered with algae and sponges that settle and grow among the spines, concealing the animal altogether. The bright colors and patterns are only revealed with careful cleaning. It can be found from North Carolina and Texas to Brazil, in shallow to moderately deep water. Spectacular specimens are often collected by divers from the legs of oil drilling platforms.
Imperial Sun Trochus, Astraea heliotropium
This famous marine shell is also known as the Sunburst Star Turban and was much sought after by elite collectors in the nineteenth century. It was first brought to Europe by Captain Cook, whose crew had brought it up from the sea bed on ships’ cables in the straits between the North and South Islands of New Zealand. It is endemic to that country, where it lives in shallow water and feeds on marine vegetation.
Teramachi’s Slit Shell, Bayerotrochus teramachii
This is a slit shell, one of fewer than 30 surviving species in an ancient family that was very abundant in all oceans from the Cambrian to the end of the Cretaceous era. The slit is a natural feature; it forms a duct that channels water out of the animal’s gill cavity. Slit shells have long been known as fossils but were thought extinct before a living one was found for the first time off the West Indies in 1879. They have since been found in South Africa, Australia, Japan and elsewhere.
Rough Pen Shell, Pinna rudis
Pen shells are large bivalves that attach themselves to the sea bed with strong, iridescent fibers known as byssus. This is the famous “golden fleece” of Greek myth; woven into a fine yarn called “sea silk” it has been used to make fine gloves, stockings and other items. The large animal is an important food item in many places and is still fished from shallow water by divers wearing traditional suits with metal helmets. The Rough Pen Shell is found in the warmer parts of the northeast Atlantic Ocean and in the Mediterranean Sea.
Green Turban, Turbo marmoratus
Found in the Indian and tropical west Pacific Oceans, these large marine snails are a traditional source of food in island communities. Tools and ornaments made from their thick shells are known from prehistoric sites in many parts of the Pacific, and their fine mother-of-pearl is still favored for inlay work, especially in Korea and Japan. The operculum, a trap door that seals the shell when the animal retreats inside, is thick and heavy.
Flinders’s Vase, Altivasum flindersi
Named for Matthew Flinders, the famous explorer who discovered much of Australia, this rare marine species is known only from the southern part of that country. It varies widely in color, from white to deep red and lavender. Large, perfect specimens still command high prices from collectors.
False Melon, Livonia mammilla
The False Melon is named for its resemblance to its larger relative, the Melon Shell. A nocturnal marine carnivore, it feeds on mud-dwelling invertebrates. The large, bulb-like end is actually the preserved infant shell, which is set at an angle to the adult shell. This species is known only from southeastern Australia.
Yoka Star Turban, Guildfordia yoka
This spectacular marine species was originally thought endemic to Japan but has since also been found in the Philippines. Its long spines are sometimes curled, and in very rare cases they are missing altogether. It lives in deep water on mud bottoms, where it feeds on detritus.
Glory-of-the-seas Cone, Conus gloriamaris
This formerly rare marine species belongs to a huge family of carnivorous snails that use powerful venoms to paralyze their prey. Depending on the species, their target can be fish, worms or other mollusks. Strong demand for their gorgeously patterned shells among nineteenth-century collectors led to the creation of convincing fakes from wood, clay or other shells. Most specimens nowadays are from the Philippines, where the species lives in moderately deep water and is active at night.
Beech Cone, Conus betulinus
This common marine species inhabits the Indo-West Pacific region. It is often found on mud near river mouths, where it feeds on worms. Its large, heavy shell is covered in life by a thick brown skin that bears thousands of fine ridges. This protects the shell from drilling organisms and the dissolving effects of low-salinity water. Once it is removed, the characteristic pattern of spots and stripes is revealed.
Hammer Oyster, Malleus albus
These tropical marine bivalves live attached to solid surfaces on the sea bed. Their shells resemble those of other oyster families in having a layered, pastry-like construction and a partial mother-of-pearl lining inside. There are several species of Hammer Oyster, all sharing the characteristic “T” shape.
Gibbon’s Sundial Snail, Solaropsis gibboni
This large and impressive land snail is found in rain forests from Costa Rica to Brazil. It is a pulmonate, meaning that it breathes air directly with a primitive lung and lacks an operculum or “trap door” to close its shell. These shells are still quite rare in collections as their habitat is often deep within the jungle in areas that are not easily accessible.
Quadras’s Amphidromus, Amphidromus quadrasi
The Amphidromus snails of the Philippines and Indonesia are unusual in that - as their name implies - their shells can coil either clockwise or anti-clockwise, sometimes even within the same species. They also vary greatly in color and pattern between localities, often making it difficult to define the species. This color form was named versicolor by Fulton in 1896, but is thought to be a local variant of quadrasi. In common with the myriad other animals of the tropical jungles in their region, the habitats of the Amphidromus snails are seriously threatened by agriculture and mining.
Manus Green Snail, Papustyla pulcherrima
This distinctive tree snail is endemic to rain forests on Manus Island in Papua New Guinea. Its vivid color and glossy shell have long made it a favorite with collectors and shell crafters. However, pressure on its habitat due to logging and agriculture has earned it a place on the official CITES list of endangered species.
Elephant Tusk Shell, Dentalium elephantinum
The tusk shells are a separate group from the snails, clams and other mollusks, and are known from all world oceans. They are thought to be the last molluscan class to evolve, though much remains to be learned about their derivation. Fully marine, they live partly buried in mud and sand on the sea bed. Historically, their distinctive shells were used as money and decoration by societies in different parts of the world. The bright green Elephant Tusk is found from the Red Sea to the Philippines and is relatively common.
West Indian Green Chiton, Chiton tuberculatus
The chitons are a major group of marine mollusks that are distinguished by having eight overlapping shells bound together by a leathery “girdle.” This flexible arrangement allows chitons to form themselves to the rock surfaces on which they mostly live, making them hard to dislodge. They feed mostly on algae using rasping teeth that are tipped with metal compounds, and their shells house thousands of primitive light-sensitive eyes. Much remains unknown about this large, cosmopolitan group. The common West Indian Green Chiton is found all over the Caribbean and in Florida, where it lives on rocky shores.
Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
Translate with Google