Parameter Tree:
EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > LAMP SHELLS

Definition:
Phylum Brachiopoda are a group of marine lophotrochozoans with hard shells on upper and lower surfaces, hinged at the rear with a pedicle projecting from one of the valesto keep the animal anchored to the seabed floor. Two main groups comprise brachiopods, articulate with toothed hinges and simple muscles and inarticulates with untoothed hinges and complex muscles.

Reference:
fossilmuseum.net