Majoidea

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Cladus: Pancrustacea
Superclassis: Multicrustacea
Classis: Malacostraca
Subclassis: Eumalacostraca
Superordo: Eucarida
Ordo: Decapoda
Subordo: Pleocyemata
Infraordo: Brachyura
Sectio: Eubrachyura
Subsectio: Heterotremata
Superfamilia: Majoidea
Familiae (7): Epialtidae - ?Hymenosomatidae - Inachidae - Inachoididae - Majidae - Oregoniidae - †Priscinachidae
Epialtidae - Inachidae - Inachoididae - Majidae - Mithracidae - Oregoniidae - Pisidae -

Genera incertae sedis: Paranaxia –
Name

Majoidea Samouelle, 1819
References

Hosie, A.M. & Hara, A. 2016. Description of a new species of brooding spider crab in the genus Paranaxia Rathbun, 1924 (Brachyura: Majoidea), from northern Australia and Indonesia. Full article (PDF) Zootaxa 4127(1): 121–134. DOI: 10.11646/zootaxa.4127.1.6. Reference page.
Naderloo, R. 2015: A new species of decorator crabs, genus Menaethiops Alcock, 1895 (Crustacea: Decapoda: Brachyura: Majoidea: Epialthidae), from Abu-Musa Island, Persian Gulf, Iran. Zootaxa 3925(3): 431–437. DOI: 10.11646/zootaxa.3925.3.7. Reference page.

Vernacular names
中文: 蜘蛛蟹总科

The Majoidea are a superfamily of crabs which includes the various spider crabs.
Taxonomy

In "A classification of living and fossil genera of decapod crustaceans" De Grave and colleagues divided Majoidea into six families:[1]

Family Epialtidae
Subfamily Epialtinae
Subfamily Pisinae
Subfamily Pliosomatinae
Subfamily Tychiinae
Family Hymenosomatidae
Family Inachidae
Family Inachoididae
Family Majidae
Subfamily Eurynolambrinae
Subfamily Majinae
Subfamily Micromaiinae
Subfamily Mithracinae
Subfamily Planoterginae
Family Oregoniidae

The classification has since been revised, with subfamilies Epialtinae and Mithracinae being elevated to families and Hymenosomatidae being moved to its own superfamily. The family composition according to the World Register of Marine Species is as follows:[2]

family Epialtidae MacLeay, 1838
family Inachidae MacLeay, 1838
family Inachoididae Dana, 1851
family Macrocheiridae Dana, 1851
family Majidae Samouelle, 1819 – "true" spider crabs
family Mithracidae Balss, 1929
family Oregoniidae Garth, 1958
family †Priscinachidae Breton, 2009

Notable species within the superfamily include:

Japanese spider crab (Macrocheira kaempferi), the largest living species of crab, found on the bottom of the Pacific Ocean.
Libinia emarginata, the portly spider crab, a species of crab found in estuarine habitats on the east coast of North America.
Hyas, a genus of spider crabs, including the great spider crab (Hyas araneus), found in the Atlantic and the North Sea.
Maja squinado, sometimes called the "European long leg crab or pie faced crab" because of the way its face is shaped.
Australian majid spider crab, found off Tasmania, are known to pile up on each other, the faster-moving crabs clambering over the smaller, slower ones.[3]

There is one fossil family, Priscinachidae, represented by a single species, Priscinachus elongatus, from the Cenomanian of France.[4]

References

Sammy De Grave; N. Dean Pentcheff; Shane T. Ahyong; et al. (2009). "A classification of living and fossil genera of decapod crustaceans" (PDF). Raffles Bulletin of Zoology. Suppl. 21: 1–109. Archived from the original (PDF) on 2011-06-06.
WoRMS. "Majoidea Samouelle, 1819". World Register of Marine Species. Retrieved 23 December 2022.
Martha Holmes & Michael Gunton (2009). Life: Extraordinary Animals, Extreme Behaviour. London: BBC Books. ISBN 9781846076428.
Gérard Breton (1 September 2009). "Description of Priscinachus elongatus n. gen., n. sp., and Priscinachidae n. fam. for the earliest spider crab (Crustacea, Decapoda, Majoidea), from the French Cretaceous (Cenomanian)" (PDF). Geodiversitas (in French and English). 31 (3): 509–523. doi:10.5252/g2009n3a2. S2CID 85827715.