Discovering the Ancient Brachiopods: Evolution, Anatomy, and Importance of Lampshells

group of lophotrochozoa that superficially resemble clams and other hinge-shelled molluscs; all marine; most attached to seafloor by a stalk

brachiopods

The group of lophotrochozoa that superficially resemble clams and other hinge-shelled molluscs and are attached to the seafloor by a stalk are known as brachiopods. They are exclusively marine and have been around since the early Cambrian period, which makes them one of the oldest animal groups on Earth.

Brachiopods are often referred to as “lampshells” because of their characteristic bivalved shell, which is typically made of calcium carbonate. The two halves of the shell are joined at a hinge located on the dorsal side of the animal. The brachiopod’s soft body is contained within the shell and is suspended by a stalk (pedicle) that passes through an opening (foramen) in one of the shells.

Brachiopods are filter feeders that use a specialized feeding structure called a lophophore to capture food particles from the water. The lophophore is a horseshoe-shaped organ that surrounds the mouth and is lined with ciliated tentacles that create a water current to bring food towards it.

Although brachiopods were once abundant and diverse, their numbers have declined since the Paleozoic era. Today, they are represented by only about 300 living species, mostly found in the deep sea. Despite their relative obscurity, brachiopods are important fossils that provide valuable information about the evolution of life on Earth.

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