西莫利鯊目

西莫利鯊目; 化石時期：382.7–280 Ma PreЄ Є O S D C P T J K Pg N
	西莫利鯊
科學分類
界：	動物界 Animalia
門：	脊索動物門 Chordata
綱：	軟骨魚綱 Chondrichthyes
亞綱：	全頭亞綱 Holocephali
目：	†西莫利鯊目 Symmoriiformes; Zangerl, 1981 (sensu Maisey, 2007)
科與屬
	見正文

西莫利鯊目（學名：Symmoriida/Symmoriiformes）是一目已滅絕的全頭類^[1]，包含四個科。西莫利鯊目最早於1981年由Zangerl描述；1986年，倫德（Lund）在主觀上將其歸為戟齒鯊類（Cladodontida）的異名；梅西（Maisey）在2008年將其恢復為獨立的西莫利鯊目。^[2]西莫利鯊目最早的化石記錄可追溯至石炭紀早期，它們中的大多數在剛進入二疊紀時就滅絕了，不過杜依卡鯊屬在南非存活到了亞丁斯剋期至空谷期。^[1]然而，發現於法國^[3]和奧地利^[4]瓦蘭吉安階地層的牙齒表明，鐮鰭鯊科的成員可能一直存活到早白堊世，但這些牙齒也被認為更有可能屬於新鯊類。^[5]

化石分布

在蒙大拿州弗格斯縣的貝爾古爾奇（Bear Gulch）^[6]、印第安納州派克縣貝瑟爾採石場、阿拉斯加州金索贊採石場、日本吉福縣和俄羅斯聯邦巴什科爾托斯坦發現了西莫利鯊目的化石證據。^[7]

描述

西莫利鯊目沒有臀鰭，尾鰭分叉且外部對稱，除可能屬於本目的裂口鯊科外，西莫利鯊類的胸鰭基部都有形似鞭子的軟骨附屬物。西莫利鯊目只有一個缺少鰭棘的背鰭，位於腹鰭正上方，牙齒屬於戟齒（cladodont）。西莫利鯊目的鰭腳發育良好，但與現代鯊魚不同。

分類

戈托（Goto）等人於1988年將西莫利鯊目歸入裂口鯊目，威廉士則於1998年將西莫利鯊目歸入板鰓亞綱，賽普考斯基（Sepkoski）和梅西分別於2002年和2008年將其直接歸入軟骨魚綱下。

杜依卡鯊屬的顱骨表明西莫利鯊目屬於全頭亞綱，因其大部分顱內解剖結構（包括骨迷路和腦空間配置）都與銀鮫目相似。^[1]

本目包括以下科和屬：

†裂口鯊科 Cladoselachidae
?^[8]
- 裂口鯊屬 Cladoselache
- 馬格里布鯊屬 Maghriboselache
†杜依卡鯊屬 Dwykaselachus ^[9]
†鐵錯鯊屬 Ferromirum
Frey, Coates, Tietjen, Rücklin & Klug, 2020
- Ferromirum oukherbouchi Frey, Coates, Tietjen, Rücklin & Klug, 2020
†咽鯊屬 Gutturensis Sequeira & Coates, 2000
†考鎮鯊屬 Kawichthys
Pradel, Tafforeau, Maisey & Janvier, 2011
- Kawichthys moodiei Pradel, Tafforeau, Maisey & Janvier, 2011
†西莫利鯊科 Symmoriidae
- 針齒鯊屬 Cobelodus
- 德納鯊屬 Denaea Pruvost, 1922
- Orestiacanthus Lund, 1984
- 四齒鯊屬 Petrodus
- 西莫利鯊屬 Symmorium
†鐮鰭鯊科 Falcatidae
- Cosmoselachus
  - Cosmoselachus mehlingi Bronson, Pradel, Denton & Maisey, 2024^[10]
- 鐮鰭鯊屬 Falcatus
- †?奧扎克鯊屬 Ozarcus
- †屬 Stethacanthulus
- †?白堊擬裂齒鯊屬 Cretacladoides（可能的早白堊世西莫利鯊類）
†胸脊鯊科 Stethacanthidae
- 砧形背鯊屬 Akmonistion
- 達摩克利斯鯊屬 Damocles
- 胸脊鯊屬 Stethacanthus

畫廊

費勒裂口鯊Cladoselache fyleri
腎形西莫利鯊 Symmorium reniforme
鐮鰭鐮鰭鯊 Falcatus falcatus
阿爾套胸脊鯊（S. altonensis）
歐赫布赫鐵錯鯊 Ferromirum oukherbouchi
長身胸棘鯊 Stethacanthus productus
贊氏砧形背鯊 Akmonistion zangerli
摩氏馬格里布鯊 Maghriboselache mohamezanei

參考資料

^ ^1.0 ^1.1 ^1.2 Coates M.; Gess R.; Finarelli J.; Criswell K.; Tietjen K. A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes. Nature. 2016, 541: 208–211. PMID 28052054. doi:10.1038/nature20806.
^ Maisey, John G. The braincase in Paleozoic symmoriiform and cladoselachian sharks. Bulletin of the American Museum of Natural History. 31 October 2007, 307: 1–122. doi:10.1206/0003-0090(2007)307[1:TBIPSA]2.0.CO;2.
^ Guillaume Guinot; Sylvain Adnet; Lionel Cavin & Henri Cappetta. Cretaceous stem chondrichthyans survived the end-Permian mass extinction. Nature Communications. 2013, 4: Article number: 2669. PMID 24169620. doi:10.1038/ncomms3669.
^ Feichtinger, Iris; Engelbrecht, Andrea; Lukeneder, Alexander; Kriwet, Jürgen. New chondrichthyans characterised by cladodont-like tooth morphologies from the Early Cretaceous of Austria, with remarks on the microstructural diversity of enameloid. Historical Biology. 2020-07-02, 32 (6): 823–836 [2022-05-22]. ISSN 0891-2963. doi:10.1080/08912963.2018.1539971. （原始內容存檔於2022-05-22）（英語）.
^ Alexander O. Ivanov. New late Carboniferous chondrichthyans from the European Russia. Bulletin of Geosciences. 2022, 97 (2) [2022-05-22]. doi:10.3140/bull.geosci.1845. （原始內容存檔於2022-03-17）.
^ Lund R. Harpagofututor volsellorhinus new genus and species (Chondrichthyes, Chondrenchelyiformes) from the Namurian Bear Gulch Limestone, Chondrenchelys problematica Traquair (Visean), and their sexual dimorphism. Journal of Paleontology. 1982., 56: 938–958. 請檢查|date=中的日期值 (幫助), authorized by John Alroy, Paleobiology Database: Bear Gulch site （頁面存檔備份，存於網際網路檔案館）
^ A.Ivanov A. Early Permian chondrichthyans of the middle and south Urals. Revista Brasileira de Paleontologia. 2005, 8( (2): 127–138.
^ Klug, Christian; Coates, Michael; Frey, Linda; Greif, Merle; Jobbins, Melina; Pohle, Alexander; Lagnaoui, Abdelouahed; Haouz, Wahiba Bel; Ginter, Michal. Broad snouted cladoselachian with sensory specialization at the base of modern chondrichthyans. Swiss Journal of Palaeontology. March 2023, 142 (1): 2. ISSN 1664-2376. PMC 10050047 . PMID 37009301. doi:10.1186/s13358-023-00266-6  （英語）.
^ Michael I. Coates, Robert W. Gess, John A. Finarelli, Katharine E. Criswell and Kristen Tietjen. 2017. A Symmoriiform Chondrichthyan Braincase and the Origin of Chimaeroid Fishes. Nature. DOI: 10.1038/nature20806
^ Allison W. Bronson, Alan Pradel, John S. S. Denton and John G. Maisey. 2024. A New operculate symmoriiform chondrichthyan from the Late Mississippian Fayetteville Shale (Arkansas, United States). GEODIVERSITAS. 46(4); 101-117.

MacInnes, D. G. 1936, "A new genus of fossil deer from the Miocene of Africa", Journal of the Linnean Society, Zoology 39: 521–530.
Hamilton, W. R., 1978, "Cervidae and Palaeomerycidae", 495–508, in Maglio, V. J. & Cooke, H. B. S., (eds.) "Evolution of African mammals", Harvard University Press, Cambridge, Massachusetts & London, England, 1978, xiv-641
https://web.archive.org/web/20081019121413/http://palaeo.gly.bris.ac.uk/benton/vertclass.html

[:0-1] 1.0 ^1.1 ^1.2 Coates M.; Gess R.; Finarelli J.; Criswell K.; Tietjen K. A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes. Nature. 2016, 541: 208–211. PMID 28052054. doi:10.1038/nature20806.

[2] Maisey, John G. The braincase in Paleozoic symmoriiform and cladoselachian sharks. Bulletin of the American Museum of Natural History. 31 October 2007, 307: 1–122. doi:10.1206/0003-0090(2007)307[1:TBIPSA]2.0.CO;2.

[3] Guillaume Guinot; Sylvain Adnet; Lionel Cavin & Henri Cappetta. Cretaceous stem chondrichthyans survived the end-Permian mass extinction. Nature Communications. 2013, 4: Article number: 2669. PMID 24169620. doi:10.1038/ncomms3669.

[4] Feichtinger, Iris; Engelbrecht, Andrea; Lukeneder, Alexander; Kriwet, Jürgen. New chondrichthyans characterised by cladodont-like tooth morphologies from the Early Cretaceous of Austria, with remarks on the microstructural diversity of enameloid. Historical Biology. 2020-07-02, 32 (6): 823–836 [2022-05-22]. ISSN 0891-2963. doi:10.1080/08912963.2018.1539971. （原始內容存檔於2022-05-22）（英語）.

[5] Alexander O. Ivanov. New late Carboniferous chondrichthyans from the European Russia. Bulletin of Geosciences. 2022, 97 (2) [2022-05-22]. doi:10.3140/bull.geosci.1845. （原始內容存檔於2022-03-17）.

[6] Lund R. Harpagofututor volsellorhinus new genus and species (Chondrichthyes, Chondrenchelyiformes) from the Namurian Bear Gulch Limestone, Chondrenchelys problematica Traquair (Visean), and their sexual dimorphism. Journal of Paleontology. 1982., 56: 938–958. 請檢查|date=中的日期值 (幫助), authorized by John Alroy, Paleobiology Database: Bear Gulch site （頁面存檔備份，存於網際網路檔案館）

[7] A.Ivanov A. Early Permian chondrichthyans of the middle and south Urals. Revista Brasileira de Paleontologia. 2005, 8( (2): 127–138.

[8] Klug, Christian; Coates, Michael; Frey, Linda; Greif, Merle; Jobbins, Melina; Pohle, Alexander; Lagnaoui, Abdelouahed; Haouz, Wahiba Bel; Ginter, Michal. Broad snouted cladoselachian with sensory specialization at the base of modern chondrichthyans. Swiss Journal of Palaeontology. March 2023, 142 (1): 2. ISSN 1664-2376. PMC 10050047 . PMID 37009301. doi:10.1186/s13358-023-00266-6  （英語）.

[9] Michael I. Coates, Robert W. Gess, John A. Finarelli, Katharine E. Criswell and Kristen Tietjen. 2017. A Symmoriiform Chondrichthyan Braincase and the Origin of Chimaeroid Fishes. Nature. DOI: 10.1038/nature20806

[10] Allison W. Bronson, Alan Pradel, John S. S. Denton and John G. Maisey. 2024. A New operculate symmoriiform chondrichthyan from the Late Mississippian Fayetteville Shale (Arkansas, United States). GEODIVERSITAS. 46(4); 101-117.

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