無螯下目

無螯下目; 化石時期：晚侏羅世 – 現在 PreЄ Є O S D C P T J K Pg N
	葉形幼體是無螯下目的典型特徵
科學分類
界：	動物界 Animalia
門：	節肢動物門 Arthropoda
亞門：	甲殼亞門 Crustacea
綱：	軟甲綱 Malacostraca
目：	十足目 Decapoda
亞目：	抱卵亞目 Pleocyemata
下目：	無螯下目 Achelata; Scholtz & Richter, 1995
科
	見正文

無螯下目（Achelata），也稱無螯蝦下目，是十足目抱卵亞目下的一個下目。

描述

無螯下目得名於其下的蝦沒有螯這一事實，「Achelata」來自希臘語，其中α-即a-為「沒有」之意，χηλή即chela為「螯」之意。它們擁有擴大的觸鬚，幼體則為特殊的葉形幼體。^[2]

分類

無螯下目包含龍蝦科和蟬蝦科這兩個現存科，^[3] 另外還有坎蝦科和三脊蝦科這兩個已滅絕科。^[1]

龍蝦科 Palinuridae Latreille, 1802
蟬蝦科 Scyllaridae Latreille, 1825
†坎蝦科（英語：Cancrinos） Cancrinos Beurlen, 1930
†三脊蝦科（英語：Tricarina）? Tricarina Feldmann et al., 2007

無螯下目下的現存物種

龍蝦科的棘刺龍蝦

蟬蝦科的Scyllarides latus

兩個現存科的化石記錄都可以追溯到白堊紀。^[4]^[5] 另外兩個化石科都只有一個屬，^[6] 其中坎蝦科生活於侏羅紀至白堊紀之間。^[5] 也有人認為無螯下目的化石記錄可以追溯到3億4100萬年前。^[7]

參考資料

^ ^1.0 ^1.1 Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong; et al. A classification of living and fossil genera of decapod crustaceans (PDF). Raffles Bulletin of Zoology. 2009,. Suppl. 21: 1–109 [2013-04-23]. （原始內容存檔 (PDF)於2011-06-06）.
^ Gerhard Scholtz & Stefan Richter. Phylogenetic systematics of the reptantian Decapoda (Crustacea, Malacostraca) (PDF). Zoological Journal of the Linnean Society. 1995, 113 (3): 289–328 [2013-04-23]. doi:10.1006/zjls.1995.0011. （原始內容存檔 (PDF)於2020-10-25）.
^ Ferran Palero, Keith A. Crandall, Pere Abelló, Enrique Macpherson & Marta Pascual. Phylogenetic relationships between spiny, slipper and coral lobsters (Crustacea, Decapoda, Achelata). Molecular Phylogenetics and Evolution. 2009, 50 (1): 152–162. PMID 18957325. doi:10.1016/j.ympev.2008.10.003.
^ Francisco J. Vega, Pedro García-Barrera, María del Carmen Perrilliat, Marco A. Coutiño & Ricardo Mariño-Pérez. El Espinal, a new plattenkalk facies locality from the Lower Cretaceous Sierra Madre Formation, Chiapas, southeastern Mexico (PDF). Revista Mexicana de Ciencias Geológicas. 2006, 23 (3): 323–333 [2013-04-23]. （原始內容存檔 (PDF)於2017-08-13）.
^ ^5.0 ^5.1 Joachim T. Haug, Carolin Haug, Dieter Waloszek, Andreas Maas, Matthias Wulf & Günter Schweigert. Development in Mesozoic scyllarids and implications for the evolution of Achelata (Reptantia, Decapoda, Crustacea) (PDF). Palaeodiversity. 2009, 2: 97–110 [2013-04-23]. （原始內容存檔 (PDF)於2021-03-09）.
^ Rodney M. Feldmann, Ali Kolahdouz, Bijan Biranvand & Guenter Schweigert. A new family, genus, and species of lobster (Decapoda: Achelata) from the Gadvan Formation (Early Cretaceous) of Iran (PDF). Journal of Paleontology. 2007, 81 (2): 405–407 [2013-04-23]. doi:10.1666/0022-3360(2007)81[405:ANFGAS]2.0.CO;2. （原始內容 (PDF)存檔於2016-03-04）.
^ Keith A. Crandall, Megan L. Porter & Marcos Pérez-Losada. Crabs, shrimps and lobsters (Decapoda). S. Blair Hedges & Sudhir Kumar (編). The Timetree of Life. Oxford University Press. 2009: 293–297. ISBN 978-0-19-160898-8.

外部連結

維基共享資源上的相關多媒體資源：無螯下目

[Grave-1] 1.0 ^1.1 Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong; et al. A classification of living and fossil genera of decapod crustaceans (PDF). Raffles Bulletin of Zoology. 2009,. Suppl. 21: 1–109 [2013-04-23]. （原始內容存檔 (PDF)於2011-06-06）.

[2] Gerhard Scholtz & Stefan Richter. Phylogenetic systematics of the reptantian Decapoda (Crustacea, Malacostraca) (PDF). Zoological Journal of the Linnean Society. 1995, 113 (3): 289–328 [2013-04-23]. doi:10.1006/zjls.1995.0011. （原始內容存檔 (PDF)於2020-10-25）.

[3] Ferran Palero, Keith A. Crandall, Pere Abelló, Enrique Macpherson & Marta Pascual. Phylogenetic relationships between spiny, slipper and coral lobsters (Crustacea, Decapoda, Achelata). Molecular Phylogenetics and Evolution. 2009, 50 (1): 152–162. PMID 18957325. doi:10.1016/j.ympev.2008.10.003.

[4] Francisco J. Vega, Pedro García-Barrera, María del Carmen Perrilliat, Marco A. Coutiño & Ricardo Mariño-Pérez. El Espinal, a new plattenkalk facies locality from the Lower Cretaceous Sierra Madre Formation, Chiapas, southeastern Mexico (PDF). Revista Mexicana de Ciencias Geológicas. 2006, 23 (3): 323–333 [2013-04-23]. （原始內容存檔 (PDF)於2017-08-13）.

[Haug-5] 5.0 ^5.1 Joachim T. Haug, Carolin Haug, Dieter Waloszek, Andreas Maas, Matthias Wulf & Günter Schweigert. Development in Mesozoic scyllarids and implications for the evolution of Achelata (Reptantia, Decapoda, Crustacea) (PDF). Palaeodiversity. 2009, 2: 97–110 [2013-04-23]. （原始內容存檔 (PDF)於2021-03-09）.

[6] Rodney M. Feldmann, Ali Kolahdouz, Bijan Biranvand & Guenter Schweigert. A new family, genus, and species of lobster (Decapoda: Achelata) from the Gadvan Formation (Early Cretaceous) of Iran (PDF). Journal of Paleontology. 2007, 81 (2): 405–407 [2013-04-23]. doi:10.1666/0022-3360(2007)81[405:ANFGAS]2.0.CO;2. （原始內容 (PDF)存檔於2016-03-04）.

[7] Keith A. Crandall, Megan L. Porter & Marcos Pérez-Losada. Crabs, shrimps and lobsters (Decapoda). S. Blair Hedges & Sudhir Kumar (編). The Timetree of Life. Oxford University Press. 2009: 293–297. ISBN 978-0-19-160898-8.

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