Polychelida

Polychelida
	Proeryon hartmanni
Systematics
Trunk :	Arthropod (arthropoda)
Class :	Higher crabs (Malacostraca)
Order :	Decapods (decapoda)
Subordination :	Pleocyemata
Partial order :	Polychelida
Scientific name
	Polychelida
	Scholtz & Richter 1995

The Polychelida are a suborder of the decapods (Decapoda). The oldest fossils of these crabs come from the Upper Triassic .

features

A characteristic and name-giving feature of the Polychelida are the real scissors on the first four pairs of striding legs . Another autapomorphy is the amalgamation of ischium and merus in pairs of striding legs two to five. On the anterior edges of the pleurae of the first abdominal segment there is a type of nub or knob. The corresponding counterpart where this knob can be hooked is located on the rear edge of the carapace .

Systematics

Phylogeny of the Polychelida according to Ahyong 2009

† Tetrachelidae

† Eryonidae

† Palaeopentachelidae

	† Coleiidae

	Polychelidae

Together with the groups of the Achelata , the species of the Polychelida formed the lobster-like (Palinura). Due to the paraphyly of this taxon, Gerhard Scholtz and Stefan Richter established the polychelida.

The Polychelida are divided into five families with a total of 93 species, of which only 38 of the Polychelidae are not extinct.

† Coleiidae Van Straelen, 1924
† Eryonidae De Haan, 1841
† Palaeopentachelidae Ahyong, 2009
Polychelidae Wood-Mason, 1875
† Tetrachelidae Beurlen, 1930

Individual evidence

↑ ^a ^b Gerhard Scholtz and Stefan Richter: Phylogenetic systematics of the reptantian Decapoda (Crustacea, Malacostraca) . In: Zoological Journal of the Linnean Society . tape 113 , 1995, pp. 289–328 ( pdf 2.7Mb [accessed on August 16, 2012]).
↑ ^a ^b Shane T. Ahyong: The Polychelidan lobsters: Phylogeny and systematics (Polychelida: Polychelidae) . In: Joel W. Martin, Keith A. Crandall, Darryl L. Felder (Eds.): Decapod Crustacean Phylogenetics . CRC Press, Boca Raton, London, New York 2009, ISBN 1-4200-9258-8 , pp. 369–396 ( PDF 2.4MB [accessed August 16, 2012]).
↑ Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong et al .: A classification of living and fossil genera of decapod crustaceans . In: Raffles Bulletin of Zoology . Suppl. 21. 2009, p. 1–109 ( PDF 7.73MB [accessed August 16, 2012]).

Web links

Commons : Polychelida - collection of images, videos and audio files

[Scholz-1] Gerhard Scholtz and Stefan Richter: Phylogenetic systematics of the reptantian Decapoda (Crustacea, Malacostraca) . In: Zoological Journal of the Linnean Society . tape 113 , 1995, pp. 289–328 ( pdf 2.7Mb [accessed on August 16, 2012]).

[Ahyong-2] Shane T. Ahyong: The Polychelidan lobsters: Phylogeny and systematics (Polychelida: Polychelidae) . In: Joel W. Martin, Keith A. Crandall, Darryl L. Felder (Eds.): Decapod Crustacean Phylogenetics . CRC Press, Boca Raton, London, New York 2009, ISBN 1-4200-9258-8 , pp. 369–396 ( PDF 2.4MB [accessed August 16, 2012]).

[Grave-3] Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong et al .: A classification of living and fossil genera of decapod crustaceans . In: Raffles Bulletin of Zoology . Suppl. 21. 2009, p. 1–109 ( PDF 7.73MB [accessed August 16, 2012]).