頂囊蕨

顶囊蕨属; 化石时期：433–393 Ma PreЄ Є O S D C P T J K Pg N 志留紀中期–泥盆紀早期
	頂囊蕨的復原圖
科学分类
界：	植物界 Plantae
演化支：	链型植物 Streptophyta
演化支：	膜生植物 Phragmoplastophyta
演化支：	有胚植物 Embryophyta
总门：	多孢植物总门 Polysporangiomorpha
属：	†顶囊蕨属 Cooksonia; Lang, 1937 emend. Gonez & Gerrienne, 2010 non Druce 1905
種
	見內文

頂囊蕨（學名：Cooksonia），又名庫氏裸蕨、庫克遜蕨、光蕨，是一屬已滅絕的原始陸生有胚植物，也是最早期的有胚植物之一，最早出現在古生代志留紀。其殘體的化石常被發現於淺海或河流三角洲的沉積岩中。^[4]

特徵

頂囊蕨繪圖

目前我們僅知道頂囊蕨的孢子體階段。它們的个体纤细，直径约2mm、高约10cm。結構簡單，未發現有根、花及葉片^[1]，莖具有維管組織。枝條有Y形分叉，最簡單的標本只由一至二個分叉組成，但也有發現有五、六層分叉的個體。每條分差的末梢上有一短且寬的孢子囊，呈喇叭形、橢圓形或腎形，內含有許多具抵抗性孢衣的孢子。^[4]

物種

Cooksonia pertoni
Cooksonia paranensis

由於標本保存較差，以下五個物種的確定性是存疑的，但目前仍被歸於本屬之下：

Cooksonia acuminata
Cooksonia bohemica
Cooksonia cambrensis
Cooksonia downtonensis
Cooksonia rusanovii

以下四個物種現時已被置入其他屬之下或已廢棄。

C. hemisphaerica Lang, 1937
C. crassiparietilis Yurina, 1964
C. caledonica Edwards, 1970 = Aberlemnia caledonica (Edwards, 1970) Gonez & Gerrienne, 2010^[5]
C. banksii Habgood et al., 2002 = Concavatheca banksii (Habgood, Edwards & Axe, 2002) Morris et al., 2012b

參考文獻

^ ^1.0 ^1.1 C. Kevin Boyce. How green was Cooksonia? The importance of size in understanding the early evolution of physiology in the vascular plant lineage. Paleobiology. 2008, 34 (2): 179－194 [2009-11-01]. doi:10.1666/0094-8373(2008)034[0179:HGWCTI]2.0.CO;2. （原始内容存档于2011-07-26）.
^ D. Edwards. Records of Cooksonia-type sporangia from late Wenlock strata in Ireland. Nature. 1980, 287: 41－42. doi:10.1038/287041a0.
^ Gonez, P. & Gerrienne, P., A New Definition and a Lectotypification of the Genus Cooksonia Lang 1937, International Journal of Plant Sciences, 2010a, 171 (2): 199–215, doi:10.1086/648988
^ ^4.0 ^4.1 Walker, Cyril（英语：Cyril Walker (palaeontologist)）; Ward, David. Fossils. Smithsonian Handbooks revised, illustrated. Dorling Kindersley. 2002: 289. ISBN 0789489848.
^ Gonez, P. & Gerrienne, P., Aberlemnia caledonica gen. et comb. nov., a new name for Cooksonia caledonica Edwards 1970, Review of Palaeobotany and Palynology, 2010b, 163 (1–2): 64–72, doi:10.1016/j.revpalbo.2010.09.005

外部連結

[Boyce2008-1] 1.0 ^1.1 C. Kevin Boyce. How green was Cooksonia? The importance of size in understanding the early evolution of physiology in the vascular plant lineage. Paleobiology. 2008, 34 (2): 179－194 [2009-11-01]. doi:10.1666/0094-8373(2008)034[0179:HGWCTI]2.0.CO;2. （原始内容存档于2011-07-26）.

[Edwards1980-2] D. Edwards. Records of Cooksonia-type sporangia from late Wenlock strata in Ireland. Nature. 1980, 287: 41－42. doi:10.1038/287041a0.

[GonezGerrienne2010a-3] Gonez, P. & Gerrienne, P., A New Definition and a Lectotypification of the Genus Cooksonia Lang 1937, International Journal of Plant Sciences, 2010a, 171 (2): 199–215, doi:10.1086/648988

[Fossils-4] 4.0 ^4.1 Walker, Cyril（英语：Cyril Walker (palaeontologist)）; Ward, David. Fossils. Smithsonian Handbooks revised, illustrated. Dorling Kindersley. 2002: 289. ISBN 0789489848.

[GonezGerrienne2010b-5] Gonez, P. & Gerrienne, P., Aberlemnia caledonica gen. et comb. nov., a new name for Cooksonia caledonica Edwards 1970, Review of Palaeobotany and Palynology, 2010b, 163 (1–2): 64–72, doi:10.1016/j.revpalbo.2010.09.005

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