The Majoidea are a
superfamily
SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...
of
crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
s 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:
* Family
Epialtidae
Epialtidae is a family of crabs, containing the subfamilies:
* Epialtinae MacLeay, 1838
* Pisinae
Pisinae is a subfamily of crabs in the family Epialtidae, comprising the following genera:
* '' Acanthophrys'' A. Milne-Edwards, 1865
* '' Ana ...
** Subfamily
Epialtinae
Epialtinae is a subfamily of crabs, containing the following genera:
* ''Acanthonyx'' Latreille, 1828
* '' Alfredalcockia'' Števčić, 2005
* '' Antilibinia'' MacLeay, 1838
* '' Cyclonyx'' Miers, 1879
* '' Epialtoides'' Garth, 1958
* '' Epialt ...
** Subfamily
Pisinae
Pisinae is a subfamily of crabs in the family Epialtidae, comprising the following genera:
* '' Acanthophrys'' A. Milne-Edwards, 1865
* '' Anamathia'' Smith, 1885
* '' Apias'' Rathbun, 1897
* '' Apiomithrax'' Rathbun, 1897
* '' Austrolibinia'' G ...
** Subfamily
Pliosomatinae
** Subfamily
Tychiinae
* Family
Hymenosomatidae
Hymenosomatidae is a family of crabs with some 110 described species in nearly 20 genera. The following genera are placed in the Hymenosomatidae:
*'' Amarinus''
*'' Apechocinus''
*'' Cancrocaeca''
*'' Crustaenia''
*'' Elamena''
*'' Elamenopsis ...
* Family
Inachidae
Inachidae is a family of crabs, containing 39 genera:
*'' Achaeopsis'' Stimpson, 1857
*'' Achaeus'' Leach, 1815
*'' Anisonotus'' A. Milne-Edwards, 1879
*'' Anomalothir'' Miers, 1879
*'' Bothromaia'' Williams & Moffitt, 1991
*'' Calypsachaeus'' ...
* Family
Inachoididae
Inachoididae is a family of crabs originally erected by James Dwight Dana
James Dwight Dana FRS FRSE (February 12, 1813 – April 14, 1895) was an American geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of m ...
* Family
Majidae
Majidae is a family of crabs, comprising around 200 marine species inside 52 genera, with a carapace that is longer than it is broad, and which forms a point at the front. The legs can be very long in some species, leading to the name "spider c ...
** Subfamily
Eurynolambrinae
** Subfamily
Majinae
** Subfamily
Micromaiinae
** Subfamily
Mithracinae
** Subfamily
Planoterginae
* Family
Oregoniidae
The Oregoniidae are a family of crabs, formerly included in the family Majidae. It contains the four genera ''Chionoecetes'', ''Hyas
Hyas ( grc, Ὑάς, Hūás, ; ), in Greek mythology, was a Boeotian who was regarded as the ancestor of the a ...
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
The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms.
Content
The content of the registry is edited and maintained by scientific specialist ...
is as follows:
* family
Epialtidae
Epialtidae is a family of crabs, containing the subfamilies:
* Epialtinae MacLeay, 1838
* Pisinae
Pisinae is a subfamily of crabs in the family Epialtidae, comprising the following genera:
* '' Acanthophrys'' A. Milne-Edwards, 1865
* '' Ana ...
MacLeay, 1838
* family
Inachidae
Inachidae is a family of crabs, containing 39 genera:
*'' Achaeopsis'' Stimpson, 1857
*'' Achaeus'' Leach, 1815
*'' Anisonotus'' A. Milne-Edwards, 1879
*'' Anomalothir'' Miers, 1879
*'' Bothromaia'' Williams & Moffitt, 1991
*'' Calypsachaeus'' ...
MacLeay, 1838
* family
Inachoididae
Inachoididae is a family of crabs originally erected by James Dwight Dana
James Dwight Dana FRS FRSE (February 12, 1813 – April 14, 1895) was an American geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of m ...
Dana, 1851
* family
Macrocheiridae Dana, 1851
* family
Majidae
Majidae is a family of crabs, comprising around 200 marine species inside 52 genera, with a carapace that is longer than it is broad, and which forms a point at the front. The legs can be very long in some species, leading to the name "spider c ...
Samouelle, 1819 – "true" spider crabs
* family
Mithracidae
Mithracidae is a family of crustaceans belonging to the order Decapoda.
Genera
Genera:
*''Ala''
*'' Amphithrax''
*''Hemus''
*'' Maguimithrax''
*'' Microphrys''
*'' Mithraculus''
*'' Mithrax''
*'' Nemausa''
*'' Nonala''
*'' Omalacantha ...
Balss, 1929
* family
Oregoniidae
The Oregoniidae are a family of crabs, formerly included in the family Majidae. It contains the four genera ''Chionoecetes'', ''Hyas
Hyas ( grc, Ὑάς, Hūás, ; ), in Greek mythology, was a Boeotian who was regarded as the ancestor of the a ...
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
''Libinia emarginata'', the portly spider crab, common spider crab or nine-spined spider crab, is a species of stenohaline crab that lives on the Atlantic coast of North America.
Distribution
''Libinia emarginata'' occurs from Nova Scotia to th ...
'', the ''portly spider crab'', a species of crab found in estuarine habitats on the east coast of North America.
* ''
Hyas
Hyas ( grc, Ὑάς, Hūás, ; ), in Greek mythology, was a Boeotian who was regarded as the ancestor of the ancient Hyantes (Boeotians). His name means rain from ''hyô, hyetos.''
Family
Hyas was the son of the Titan Atlas and either of the ...
'', 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
Australian(s) may refer to:
Australia
* Australia, a country
* Australians, citizens of the Commonwealth of Australia
** European Australians
** Anglo-Celtic Australians, Australians descended principally from British colonists
** Aboriginal Au ...
'', found off Tasmania, are known to pile up on each other, the faster-moving crabs clambering over the smaller, slower ones.
There is one fossil family, Priscinachidae, represented by a single species, ''
Priscinachus elongatus'', from the
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...
of France.
Image:Candy crab.jpg, ''Hoplophrys oatesi
''Hoplophrys'' is a monotypic genus of crab in the Family (biology), family Epialtidae. It contains the single species Hoplophrys oatesi, also known as the candy crab, Oates's soft coral crab, commensal soft coral crab and ''Dendronephthya'' cr ...
'', an Epialtidae
Epialtidae is a family of crabs, containing the subfamilies:
* Epialtinae MacLeay, 1838
* Pisinae
Pisinae is a subfamily of crabs in the family Epialtidae, comprising the following genera:
* '' Acanthophrys'' A. Milne-Edwards, 1865
* '' Ana ...
Image:Limnopilos naiyanetri - (4).jpg, ''Limnopilos naiyanetri
''Limnopilos naiyanetri'', commonly referred to as the Thai micro crab or pill-box crab, is a freshwater hymenosomatid crab endemic to Thailand. Its presence has only been confirmed in the Tha Chin River. The species was described in 1991 and r ...
'', a Hymenosomatidae
Hymenosomatidae is a family of crabs with some 110 described species in nearly 20 genera. The following genera are placed in the Hymenosomatidae:
*'' Amarinus''
*'' Apechocinus''
*'' Cancrocaeca''
*'' Crustaenia''
*'' Elamena''
*'' Elamenopsis ...
Image:Macrocheira kaempferi.jpg, ''Macrocheira kaempferi
The Japanese spider crab (''Macrocheira kaempferi'') is a species of marine crab that lives in the waters around Japan. It has the largest known leg-span of any arthropod. It goes through three main larval stages along with a prezoeal stage to ...
'', an Inachidae
Inachidae is a family of crabs, containing 39 genera:
*'' Achaeopsis'' Stimpson, 1857
*'' Achaeus'' Leach, 1815
*'' Anisonotus'' A. Milne-Edwards, 1879
*'' Anomalothir'' Miers, 1879
*'' Bothromaia'' Williams & Moffitt, 1991
*'' Calypsachaeus'' ...
Image:Pyromaia cuspidata.jpg, ''Pyromaia cuspidata
''Pyromaia cuspidata'', also known as the dartnose pear crab, is a species of crab in the family Inachoididae. This crab appears similar to ''Anasimus latus''. It is a long-legged crab with a trident-shaped rostrum, and occurs in Atlantic waters ...
'', an Inachoididae
Inachoididae is a family of crabs originally erected by James Dwight Dana
James Dwight Dana FRS FRSE (February 12, 1813 – April 14, 1895) was an American geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of m ...
Image:Maja squinado.jpg, '' Maja squinado'', a Majidae
Majidae is a family of crabs, comprising around 200 marine species inside 52 genera, with a carapace that is longer than it is broad, and which forms a point at the front. The legs can be very long in some species, leading to the name "spider c ...
Image:Hyas coarctatus.jpg, ''Hyas coarctatus
''Hyas coarctatus'' is a marine crab species native to the North Atlantic. It is characterized by a lyriformed shell.
Morphology
''Hyas coarctatus'' looks like the great spider crab (''H. araneus'') but has a lyriformed shell. The carapace of ...
'', an Oregoniidae
The Oregoniidae are a family of crabs, formerly included in the family Majidae. It contains the four genera ''Chionoecetes'', ''Hyas
Hyas ( grc, Ὑάς, Hūás, ; ), in Greek mythology, was a Boeotian who was regarded as the ancestor of the a ...
References
Cenomanian first appearances
Arthropod superfamilies
Extant Cenomanian first appearances
{{crab-stub