Brachiopod

Brachiopods are bivalved marine invertabrates that constitute a separate group, Brachiopoda. Brachiopods were prominent shell fish in many continental-shelf sea environments for about 250 million years, from the Ordovician into the Permian periods. In the Cambrian, some were prominent in nearshore environments. Since the end of the Paleozoic, clams appear to have been the prominent marine benthic bivalved animal in environments previously inhabited by brachiopods. Today, brachiopods are found in many habitats in nearly all of the shelf seas. …