Chamidae – Jewel Boxes

Description

 

Chama is an oyster-like bivalve that has developed a permanently attached mode of life. Its deeply conical right valve (in the pictures at right, the upper valve) is cemented to some substrate, while the somewhat flattened left valve forms an operculum-like cover. Consistent with its immobility, the foot is greatly reduced.

 

Chama is a sole surviving genus of a very prolific group of fossil oysters dating from the Jurassic and Cretaceous periods, some 200 million years ago. It is of interest mainly because it seems to occupy an intermediate evolutionary step between two extinct families of the Chamacea superfamily.

 

Classification

Class: Bivalvia

Subclass: Heterodonta

Order: Veneroida

Superfamily: Chamacea

Family: Chamidae

Major Genera

• Genus: Arcinella
• Genus: Chama
• Genus: Pseudochama

Amphichama argentata Amphichama inezae Arcinella arcinella Arcinella brasiliana Arcinella californica Arcinella cornuta Chama ambigua Chama arcana Chama asperella Chama asperella fibula Chama asperella hendersoni Chama aspersa Chama berjadinensis Chama brassica Chama brassica elatensis Chama buddiana Chama cerinorhodon Chama cerion Chama circinata Chama congregata Chama coralloides Chama crenulata Chama croceata Chama croceata savignyi Chama croceata plinthota Chama dunkeri Chama dunkeri semipurpurata Chama echinata Chama exogyra Chama florida Chama fragum Chama frondosa Chama gryphoides Chama gryphoides mioasperella Chama isaacooki Chama japonica Chama lactuca Chama lazarus Chama limbula Chama limbula iostoma Chama lobata Chama macerophylla Chama oomedusae Chama pacifica Chama pacifica reflexa Chama pellucida Chama rubropicta Chama ruderalis Chama sarda Chama sinuosa Chama sordida Chama squamuligera Chama yaroni Cipliacella supracretacea Eopseuma phyllotrapezium Pseudochama corbierei Pseudochama corrugata Pseudochama cristella Pseudochama cristella radians Pseudochama exogyra Pseudochama gryphina Pseudochama inermis Pseudochama panamensis Pseudochama picta