malacostraca

Decapods are an order of crustaceans in the class Malacostraca.

The best-known class, to which all the edible species of crustacean belong, is Malacostraca.

Some think Malacostraca is a class and others think it is a subclass.

Members of Malacostraca have compound stalked or sessile eyes.

The phylogeny of the Malacostraca is debated.

Schizopoda is a former taxonomical classification of a division of the class Malacostraca.

Malacostraca have heads with six segments.

However debate arises in the relationship between the subdivisions of the Malacostraca, due to the presence of several contrasting features.

Class Malacostraca (true crabs, lobster and most shrimp)

They are believed to represent the most primitive members of their class, the Malacostraca, and first appear in the fossil record during the Cambrian period.

Cumaceans belong to the superorder Peracarida, within the class Malacostraca.

They are divisible into two subclasses, Entomostraca and Malacostraca, each of which includes several orders.

Australian Malacostraca page with some information on W. A. Haswell.

The crustacean order Tanaidacea (known as tanaids) make up a minor group within the class Malacostraca.

Coenobita compressus is a member of the phylum Arthropoda and the class Malacostraca.

The Malacostraca (Greek: "soft shell") are the largest subgroup of crustaceans.

Most species of malacostraca have distinct sexes (a phenomenon known as gonochorism) although there are a few species that exhibit hermaphroditism.

The genus has been placed within the subclass Phyllocarida, in the class Malacostraca that includes shrimps and lobsters.

The Class Malacostraca includes over 25,000 species, and "arguably ... contains a greater diversity of body forms than any other class in the animal kingdom".

The Eumalacostraca - the malacostraca minus the phyllocarida - were subdivided on the basis of several features, although which group is basal is unclear.

It is now accepted that leptostracans belong to the Malacostraca, and the sister group to Leptostraca is Eumalacostraca.

Under the heading Crustacea, the Entomostraca have already been distinguished not only from the barnacles, but also from the Malacostraca.

Malacostracans are sometimes contrasted with entomostracans, a name applied to all crustaceans outside the Malacostraca, and named after the obsolete taxon Entomostraca.

Meinert specialised in comparative anatotomy and histology mainly of Malacostraca and Pycnogonida .

The size and complexity of the brain suggested that Remipedia might be the sister taxon to Malacostraca, regarded as the most advanced of the crustaceans.