No other organisms typify the Age of Invertebrates more than brachiopods. They are the most abundant Paleozic fossils, except for maybe trilobites. Paleontologists use them to date rocks and other fossils. Countless billions accumulated on the ocean floor with over 30,000 forms . Today there are far fewer species, only about 300 which live mostly in cold water, deep ocean environments.
Brachiopods were the first of their kind to lose mobility and develop a hard covering. They look like clams but are very different inside. To tell them apart, clams have uneven shaped left and right sides of their shells, but the tops and bottoms are identical. Brachiopods have evenly shaped (symmetrical) left and right sides of their shells, but the bottom is smaller. Thick shell forms are ribbed and live in shallow water. Thin shell forms are smooth and live in deep water. Some grow to 9 inches across, but most are about an inch in diameter. They live in communities attached to objects by a muscular foot called a pedicle. They strain water in and out of their shells filtering microorganisms with their lophophores, a crown of tentacles.
Common Name: Brachiopod or Lamp Shell (named for resemblance to ancient Roman oil lamps)
Phylum: Brachiopoda (means arm and foot)
Class: Articulated (shells clamp together by a hinge)
Inarticulated (shells clamp together by a muscle)
Genus: #1 possibly Pseudoatrypa sp / #2 possibly Atrypa,reticularis