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

Chama reflexa (Reeve, 1846)
Reflexed Jewel Box