Transverse Lamp Shell
The transverse lamp shell (Terebratalia transversa) is a brachiopod of the Pacific coast of North America. Brachiopods have two shells like clams, but are unrelated to them; they were one of the dominant animal groups of the Paleozoic.
The transverse lamp shell (Terebratalia transversa) is a brachiopod of the Pacific coast of North America. Brachiopods have two shells like clams, but are unrelated to them; they were one of the dominant animal groups of the Paleozoic.
🧬 Field Guide Specimen: Open Transverse Lamp Shell in the CRV Science Field Guide to log the specimen, see its place among the Lophotrochozoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
Not a Clam: How Can You Tell?
In a clam the two valves are left and right mirror images, whereas in a brachiopod the two valves lie on the top and bottom of the body and are different in size. A fleshy stalk (pedicle) anchors the animal. Inside, a coiled feeding organ called a lophophore filters food from the water.
Lamp Shells in Deep Time
Brachiopods are abundant in Paleozoic rocks, with tens of thousands of fossil species, and were hit hard by the end-Permian mass extinction about 252 million years ago. Only a few hundred species survive. They are widely used as index fossils.
A Developmental Model
Terebratalia has been studied for how lophophorate animals develop and for what its Hox genes reveal about the evolution of body plans in Lophotrochozoa.
Transverse Lamp Shell at a Glance
| Property | Value |
|---|---|
| Scientific name | Terebratalia transversa |
| Kingdom | Animalia |
| Phylum | Brachiopoda |
| Class | Rhynchonellata |
| Order | Terebratulida |
| Family | Terebrataliidae |
| Field Guide group | Lophotrochozoa: Worms, Shells & Allies |
| Diagnostic feature (Field Guide) | Two unequal hinged valves on its top and bottom (not left and right), a muscular stalk anchoring to rock, and an internal horseshoe-shaped feeding crown. |
| Phylum | Brachiopoda |
| Feeding organ | Lophophore |
See Also
- Evolution — living representatives of ancient groups
- Evolutionary developmental biology — Hox genes and body plans