The Decapoda or decapods are an order of crustaceans within the class Malacostraca, and includes crabs, lobsters, crayfish, shrimp, and prawns. Most decapods are scavengers. The order is estimated to contain nearly 15,000 extant species in around 2,700 genera, with around 3,300 fossil species. Nearly half of these species are crabs, with the shrimp and Anomura including hermit crabs, porcelain crabs, squat lobsters making up the bulk of the remainder. The earliest fossils of the group date to the Devonian.
Isopoda is an order of crustaceans. Members of this group are called Isopods and include both terrestrial and aquatic species such as woodlice. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, and five pairs of branching appendages on the abdomen that are used in respiration. Females brood their young in a pouch under their thorax.
The crustacean order Tanaidacea make up a minor group within the class Malacostraca. There are about 940 species in this order.
The Gnathiidae are a family of isopod crustaceans. They occur in a wide range of depths, from the littoral zone to the deep sea. The adults are associated with sponges and may not feed. The juvenile form is known as a 'praniza', and it is a temporary parasite of marine fish. These forms are not larvae; Gnathiidae instead become parasitic during the manca stage. Mancae of the Gnathiidae closely resemble the adult form, however they lack the final pair of pereiopods.
The Nevrorthidae are a small family of lacewings in the order Neuroptera. There are 19 extant species in four genera, with a geographically disjunct distribution: Nevrorthus, comprising 5 species with scattered distributions around the Mediterranean; Austroneurorthus, with two species known from southeastern Australia; Nipponeurorthus, comprising 11 species known from China and Japan; and Sinoneurorthus, known from a single species described from Yunnan Province, China. They are traditionally placed in the Osmyloidea, alongside Osmylidae and the spongillaflies (Sisyridae), but some research has considered them to be the sister group to the rest of Neuroptera. The larvae have unique straight jaws that are curved at the tips, and live as unspecialised predators in the sandy bottom sediments of clear, fast flowing mountain rivers and streams. They pupate underwater on the underside of stones. The adults are likely predators or feed on honeydew and other sugar-rich fluids.
Cymothoida is the name of a suborder of isopod crustaceans with a mostly carnivorous or parasitic lifestyle. It contains more than 2,700 described species in four superfamilies. Members of the suborder are characterised by their specialised mouthparts which include a mandible with a tooth-like process which is adapted for cutting or slicing.
Sphaeromatidea is a suborder of isopod crustaceans.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
The Bopyridae are a family of isopod crustaceans in the suborder Cymothoida. There are 1223 individual species contained in this family. Members of the family are ectoparasites of crabs and shrimp. They live in the gill cavities or under the carapace where they cause a noticeable swelling. Fossil crustaceans have occasionally been observed to have a similar characteristic bulge.
Cancricepon is a genus of isopod crustaceans in the family Bopyridae including species formerly included in the deprecated Merocepon Richardson, 1910.
The Cabiropidae are a family of isopod crustaceans in the suborder Cymothoida. The original description was made by Giard and Bonnier in 1887. Members of the family are hyperparasites of other parasitic isopods in the order and some are parasites on other free-living isopods.
The Cryptoniscidae are a family of isopod crustaceans in the suborder Cymothoida. The original description was made by Kossmann in 1880. "Liriopsidae" is a junior synonym. Members of this family are hyperparasites of rhizocephalid barnacles which are themselves parasites of decapod crustaceans. The morphology of the adult females gives little clue as to their true identity, but the free-living larvae show their true taxonomic affiliations.
The Hemioniscidae are a family of marine isopod crustaceans in the suborder Cymothoida. The original description was made by Bonnier in 1900. Members of this family are parasitic on cirripede barnacles.
The Cyproniscidae are a family of marine isopod crustaceans in the suborder Cymothoida. The original description was made by Bonnier in 1900. Members of this family are parasitic on other isopods.
The Dajidae are a family of marine isopod crustaceans in the suborder Cymothoida. The original description was made by Giard and Bonnier in 1887. Members of this family are ectoparasites of krill. They resemble a fleshy growth on the krill's back, and make the host look as if it is wearing a rucksack. These genera are included in the family Dajidae:
The Entoniscidae are a family of marine isopod crustaceans in the suborder Cymothoida. Members of this family are parasites of brachyuran and anomuran crabs, living in their hosts' haemocoel. A small chitinised hole develops through the host's exoskeleton through which the isopod can communicate with the environment. The female isopod bears little resemblance to any free-living isopod, but the morphology of the larvae show their taxonomic affiliations.
This list of fossil arthropods described in 2017 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids and other fossil arthropods of every kind that are scheduled to be described during the year 2017, as well as other significant discoveries and events related to arthropod paleontology that are scheduled to occur in the year 2017.
This list of fossil arthropods described in 2019 is a list of new taxa of trilobites, fossil insects, crustaceans, arachnids and other fossil arthropods of every kind that are scheduled to be described during the year 2019, as well as other significant discoveries and events related to arthropod paleontology that are scheduled to occur in the year 2019.
2020 in arthropod paleontology is a list of new arthropod fossil taxa, including arachnids, crustaceans, insects, trilobites, and other arthropods that were announced or described, as well as other significant arthropod paleontological discoveries and events which occurred in 2020.
This paleoentomology list records new fossil insect taxa that are to be described during the year 2022, as well as notes other significant paleoentomology discoveries and events which occurred during that year.
