Mytilida is an order of

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s, commonly known as true mussels. There is one extant superfamily, the

Mytiloidea Mytiloidea are a superfamily of small to large saltwater mussels, marine bivalve molluscs in the order Mytilida. ''Mytiloidea'' contains two families, Mysideiellidae, which is known only from fossils and Mytilidae Mytilidae are a fami ...

, with a single extant family, the Mytilidae. Species in the order Mytilida are found worldwide, but they are more abundant in colder seas, where they often form uninterrupted beds on rocky shores in the

intertidal zone The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species o ...

and the shallow subtidal. The subfamily Bathymodiolinae is found in deep-sea habitats. Mytilids include the well-known edible sea mussels. A common feature of the shells of mussels is an asymmetrical shell which has a thick, adherent

periostracum The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...

. The animals attach themselves to a solid substrate using a byssus.

2010 taxonomy

In 2010, a new proposed classification system for the Bivalvia was published by Bieler, Carter & Coan. This included the suborder Mytiloida.Bieler, R., Carter, J.G. & Coan, E.V. (2010) ''Classification of Bivalve families''. Pp. 113-133, in: Bouchet, P. & Rocroi, J.P. (2010), ''Nomenclator of Bivalve Families. Malacologia'' 52(2): 1-184 *Superfamily † Modiolopsoidea **Family † Colpomyidae **Family † Modiolopsidae **Family † Saffordiidae *Superfamily

**Family † Mysideiellidae **Family Mytilidae

References

Bivalve orders {{bivalve-stub