More Mollusks

The Ocean Blog

About 100 million years ago , during the heyday of the dinosaurs, reefs were built by mollusks called rudist clams. Like modern clams, rudists were bivalves , with two shells (or valves) joined at a...
This beautiful spider conch ( Lambis chiragra ) was collected by Census of Marine Life scientists conducting research near China.
Where ocean currents were strong, ancient rudist “recliners” lay unattached on the seabed. Notice the pink tentacles, which were used to filter feed. Learn more about ocean life throughout deep time...
A colony of 100 million flame shells ( Limaria hians ) was discovered in Scotland in 2012 , and is thought to be the biggest in the world. Flame shells are bivalve mollusks that are shaped a bit like...
Sea butterflies (also called pteropods) are sea snails aptly named: they are shelled marine snails, each with a foot like a wing, that swim in the water column like butterflies. This one, Atlanta...
Yolanda Villacampa is a museum specialist in the invertebrate zoology department of Smithsonian's National Museum of Natural History. She is standing surrounded by the invertebrate zoology collection.
This pair of sea butterflies ( Limacina helicina ) flutter not far from the ocean's surface in the Arctic. Sea butterflies are a type of sea snail, but instead of dragging themselves around the...
Nudibranchs are mollusks that have evolved from shelled ancestors. Like the reddish-orange Coryphella verrucosa shown here, they're often noted for their vibrant colors and striking forms. View other...
These Pacific cephalopods illustrate the wide diversity among this group of mollusks. You can learn about a relative, the giant squid ( Architeuthis dux ), in our Giant Squid section.
Ocean acidification is sometimes called “climate change’s equally evil twin,” and for good reason: it's a significant and harmful consequence of excess carbon dioxide in the atmosphere that we don't...
Giant clams are one of the many wonders of coral reefs. They can grow up to five feet wide, weigh over 400 pounds, and live for 100 years! They power all that bulk by filter feeding microbes and...
Rudist clams are mollusks that went extinct about 65 million years ago. They were the reef builders of the Cretaceous Period, the heyday of the dinosaurs. Today corals have taken over the role...
This illustration shows the edge of a warm inland sea during the Cretaceous Period, heyday of the dinosaurs. Constantly shifting sediment supported new groups of organisms, including rudist clams—...
What can students do to help the ocean? It turns out, a lot! These students from Texas are among dozens from the U.S. and Mexico who are developing action plans on ocean and climate-related issues in...
Rapa whelks , native to Asia, have invaded the Chesapeake Bay and are raising concerns about economic and ecological impacts to the Bay region due to their shellfish diet. Scientists believe that...
Shellfish from the Chesapeake Bay are prized by seafood lovers. But the Bay's ecosystem and fisheries are threatened by human disturbances, including the introduction of non-native species. Non-...
These "elevator" rudists, an ancient bivalve, used one long heavy valve to anchor themselves in the sediment. They used their tentacles (shown here in pink) to filter food from the sea water. And...
Regardless of what continent you live on, the waters that surround it are home to marine invaders. The ocean is teeming with plants and animals willing and able to move beyond their native habitats...
Subscribe to Mollusks