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Cryptodonta

Cryptodonta
Antipleuridae - Panenka bohemica.JPG
Panenka bohemica (Antipleuridae) from Czech Republic, at the National Museum (Prague)
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Subclass: Cryptodonta
Neumayr, 1884
Orders

The Cryptodonta are a nearly-extinct subclass of the bivalves. It contains a single extant order, Solemyoida, while the Praecardioida are known only from fossils.

The valves of the shell are relatively thin and somewhat elongated. Unlike most other bivalves, species in this group have no hinge teeth on their shells. They have relatively primitive, "protobranchiate", gills.


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Wikipedia

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