Eumalacostraca
Eumalacostraca is a subclass of crustaceans, containing almost all living malacostracans, or about 40,000 described species.[1] The remaining subclasses are the Phyllocarida and possibly the Hoplocarida.[2] Eumalacostracans have 19 segments (5 cephalic, 8 thoracic and 6 abdominal). This arrangement is known as the "caridoid facies", a term coined by William Thomas Calman in 1909. The thoracic limbs are jointed and used for swimming or walking. The common ancestor is thought to have had a carapace, and most living species possess one, but it has been lost in some subgroups. Caridoid faciesCalman identified the following features as distinguishing eumalacostracan crustaceans:[3]
ClassificationMartin and Davis present the following classification of living eumalacostracans into orders, to which extinct orders have been added, indicated by †.[2] The group as originally described by Karl Grobben[4] included the Stomatopoda (mantis shrimp), and a number of modern experts and databases (ex. NCBI) continue to use this definition. This article follows Martin and Davis in excluding them; they are placed in their own subclass, Hoplocarida. Subclass Eumalacostraca Grobben, 1892
ReferencesWikispecies has information related to Eumalacostraca.
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