Pterioida

Pteria hirundo

The Pterioida are an order of mussels ( Bivalvia ), which is provided infra class Pteriomorphia within the Autolamellibranchiata. It is an exclusively marine living mussel group. The oldest Pterioida are known from the Lower Ordovician.

Characterization

The housing of Pterioida are always more or less equivalve ( Pteroidea ) or equivalve ( Pinnoidea ). The shell is made of an inner layer with aragonitisch, pearl ring microstructures and an outer calcite layers, made ​​up of simple prisms. For some groups, these calcitic layer is missing. The castle is largely reduced. Also, the front sphincter is generally reduced more or less clearly. Most forms have a fine linen.

Way of life

The Pterioida are exclusively marine bivalve molluscs, which are usually attached to the substrate by means of organic linen. They usually live on the sediment, some forms of life also cemented to the substrate or half buried in the sediment.

System

The Pterioida include according to the latest classification of Bieler & Mikkelsen (2006) three superfamilies. Below is the superfamily Ostreoidea, which is regarded by the majority of malacologists than fine. The two remaining superfamilies

• Superfamily Pterioidea Gray, 1847 (eg family wing clams ( Pteriidae Gray, 1847) )
• Superfamily Pinnoidea Leach, 1819 (eg noble pen shell ( Pinna nobilis) )

Are guided by some authors with the rank of sub-orders. Added to this are the only fossil superfamilies

• Superfamily † Ambonychioidea Miller, 1877 Inoceramidae Giebel, 1852