Eubrachyura is a group of decapod crustaceans (ranked as a "section") comprising the more derived crabs. It is divided into two subsections, based on the position of the genital openings in the two sexes. In the Heterotremata, the openings are on the legs in the males, but on the sternum in females, while in the Thoracotremata, the openings are on the sternum in both sexes. This contrasts with the situation in other decapods, in which the genital openings are always on the legs. Heterotremata is the larger of the two groups, containing the species-rich superfamilies Xanthoidea and Pilumnoidea and all the freshwater crabs (Gecarcinucoidea, Potamoidea). The eubrachyura is well known for actively and constantly building its own burrows.[2] The fossil record of the Eubrachyura extends back to the Cretaceous;[3] the supposed Bathonian (Middle Jurassic) representative of the group, Hebertides jurassica,[4] ultimately turned out to be Cenozoic in age.[5]
Here is a cladogram showing Eubrachyura's placement within Brachyura, as well as the two subgroups Heterotremata and Thoracotremata:[6][7]
Brachyura
Dromiacea
Raninoida
Cyclodorippoida
Eubrachyura
Heterotremata
Thoracotremata
^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.
^P. K. L. Ng, D. Guinot & P. J. F. Davie (2008). "Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world" (PDF). Raffles Bulletin of Zoology. 17: 1–286. Archived from the original (PDF) on 2011-06-06.
^"Evolution of Primitive Crabs: Insights from the Neotropics". 6 November 2012.
^Danièle Guinot; Antonio de Angeli; Alessandro Garassino (2007). "Hebertides jurassica n. gen., n. sp. (Crustacea, Decapoda, Brachyura) from the Middle Jurassic (Bathonian) of Normandy (France)". Atti della Società italiana di scienze naturali e del museo civico di storia naturale di Milano. 148 (2): 241–260.
^Paul D. Taylor; G. Breton; Danièle Guinot; Antonio de Angeli; Alessandro Garassino (2012). "The Cenozoic age of the supposed Jurassic crab Hebertides jurassica Guinot, De Angeli & Gerassino, 2007 (Crustacea, Decapoda, Brachyura)". Atti della Società italiana di scienze naturali e del museo civico di storia naturale di Milano. 153 (1): 71–83. doi:10.4081/nhs.2012.71.
^Wolfe, Joanna M.; Breinholt, Jesse W.; Crandall, Keith A.; Lemmon, Alan R.; Lemmon, Emily Moriarty; Timm, Laura E.; Siddall, Mark E.; Bracken-Grissom, Heather D. (24 April 2019). "A phylogenomic framework, evolutionary timeline and genomic resources for comparative studies of decapod crustaceans". Proceedings of the Royal Society B. 286 (1901). doi:10.1098/rspb.2019.0079. PMC 6501934. PMID 31014217.
^Ling Ming Tsang; Christoph D. Schubart; Shane T. Ahyong; Joelle C.Y. Lai; Eugene Y.C. Au; Tin-Yam Chan; Peter K.L. Ng; Ka Hou Chu (2014). "Evolutionary History of True Crabs (Crustacea: Decapoda: Brachyura) and the Origin of Freshwater Crabs". Molecular Biology and Evolution. 31 (5). Oxford University Press : 1173–1187. doi:10.1093/molbev/msu068. PMID 24520090.
Eubrachyura is a group of decapod crustaceans (ranked as a "section") comprising the more derived crabs. It is divided into two subsections, based on...
Cyclodorippoida split off next, during the Jurassic period. The remaining clade Eubrachyura then divided during the Cretaceous period into Heterotremata and Thoracotremata...
group to Thoracotremata within the clade Eubrachyura, having diverged during the Cretaceous period. Eubrachyura itself is a subset of the larger clade Brachyura...
group to Heterotremata within the clade Eubrachyura, having diverged during the Cretaceous period. Eubrachyura itself is a subset of the larger clade Brachyura...
invalid. It was the smaller grouping of crabs, separate from the larger Eubrachyura section. Morphological and molecular analyses do not reveal a monophyletic...