Veneroida

Veneroida
Empty cockle shell, family Cardiidae
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Subclass:	Heterodonta
Order:	Veneroida
Families
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The Veneroida or veneroids are an order of mostly saltwater but also some freshwater bivalve molluscs. This order includes many familiar groups such as many clams and cockles that are valued for food, and a number of freshwater bivalves including the invasive species of zebra mussels.

Until recently, the Carditoida (cockles and their allies) were usually included in this group.

Veneroids are generally thick-valved, equal valved, and isomyarian (that is, their adductor muscles are of equal size). Three main hinge teeth are characteristic of the subclass Heterodonta to which this order belongs. Many species are active rather than sessile. However they tend to be filter feeders, feeding through paired siphons, with a characteristic folded gill structure adapted to that way of life.

In 2002, Gonzalo Giribet and Ward Wheeler suggested that the orders Myoida and Veneroida were not monophyletic.

Order: Veneroida

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