Brachiopod
A marine invertebrate of the phylum Brachiopoda, typically enclosed in two unequal shells and feeding with a ciliated lophophore.
Lophophore: A ciliated tentacular feeding organ found in brachiopods, bryozoans, and phoronids. Its cilia draw food-bearing water through the brachiopod shell.
Brachiopod feeding: The capture and transport of suspended food particles by a brachiopod's lophophore. Ciliary currents sort particles and move food toward the mouth.
Cambrian explosion: A major interval of animal diversification beginning about 539 million years ago. The earliest known brachiopods appear during this broad burst of animal diversity.
Articulata: A major brachiopod group whose valves are joined by a hinge with interlocking teeth and sockets. Most familiar fossil brachiopods belong to this articulated group.
Phoronida: A phylum of marine, tube-dwelling invertebrates that feed with a lophophore. Phoronids share brachiopods’ feeding organ but have elongated bodies within tubes.
Pedicle: A stalk-like structure that attaches some brachiopods to the seafloor. Many living brachiopods anchor themselves through an opening in one valve.
Brachiopod valve: One of the two shell halves of a brachiopod, joined along a hinge or margin. Muscles and internal supports control the opening of the valves.
Brachiopod evolution: The evolutionary history of brachiopods from early Paleozoic forms to living lineages. Their fossil record reveals repeated diversification, extinction, and ecological change.
Inarticulata: A traditional brachiopod grouping whose valves lack a tooth-and-socket hinge. Its members illustrate a different way of holding the two valves together.
Mollusca: A large animal phylum including snails, bivalves, and cephalopods, many of which secrete shells. Brachiopods and molluscs both have shells, but belong to distinct animal phyla.