Phylum Brachiopoda
Phylum Brachiopoda
Brachiopods are shelled invertebrate that look somewhat like bivalved molluscs. However, the animal living in the shell is a filter feeder that collects food with a special organ called a lophopore (bryzozoa also have lophophores).
Like clams, the brachiopod lives in a shell consisting of two hinged valves, but the orientation of the shells is different. Brachiopods have valves covering the top and bottoms of the animal that are of different sizes and shapes, but the left and right sides are are symmetrical (or mirror images to each other). In contrast, the valves of a clam shell are mirror images of each other, but the individual valves are asymmetrically shaped.
Brachiopods spend their adult life as bottom dwelling filter-feeders. They have generally decreased in abundance and diversity since the Paleozoic Era. Some types are fairly common, easy to identify, and are restricted to certain periods of time. These features make them important index or guide fossils. The brachiopod species Terebratulina cooperi is an index fossil for the Mount Laurel Formation in Delaware.
4. Terebratulina cooperi - specimen from the Mount Laurel Formation
Photograph from Plate 1, DGS Special Publication No. 18, by E. M. Lauginiger, 1988.
- Terebratulina cooperi - occurs in the Mount Laurel Formation
Cretaceous Brachiopoda illustrations from Figure 7, DGS Special Publication No. 18, by E. M. Lauginiger, 1988.
- Terebratulina cooperi - occurs in the Mount Laurel Formation
Cretaceous Brachiopoda illustration from Page 15, DGS Special Publication No. 19, 1992.
3. Terebratulina cooperi - specimen from the Mount Laurel Formation
Cretaceous Brachiopoda photograph from Plate VI, DGS Report of Investigation No. 21, by T. E. Pickett, 1972.
- Terebratulina cooperi - growth series, specimens found in the Mount Laurel Formation
Cretaceous Brachiopoda photographs from Plate VI, DGS Report of Investigation No. 21, by T. E. Pickett, 1972.