顶囊蕨

顶囊蕨属; 化石时期：433–393 Ma PreЄ Є O S D C P T J K Pg N 志留纪中期–泥盆纪早期
	顶囊蕨的复原图
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
种
	见内文

顶囊蕨（学名：Cooksonia），又名库氏裸蕨、库克逊蕨、光蕨，是一属已灭绝的原始陆生有胚植物，也是最早期的有胚植物之一，最早出现在古生代志留纪。其残体的化石常被发现于浅海或河流三角洲的沉积岩中。^[4]

特征

顶囊蕨绘图

目前我们仅知道顶囊蕨的孢子体阶段。它们的个体纤细，直径约2mm、高约10cm。结构简单，未发现有根、花及叶片^[1]，茎具有维管组织。枝条有Y形分叉，最简单的标本只由一至二个分叉组成，但也有发现有五、六层分叉的个体。每条分差的末梢上有一短且宽的孢子囊，呈喇叭形、椭圆形或肾形，内含有许多具抵抗性孢衣的孢子。^[4]

物种

Cooksonia pertoni
Cooksonia paranensis

由于标本保存较差，以下五个物种的确定性是存疑的，但目前仍被归于本属之下：

Cooksonia acuminata
Cooksonia bohemica
Cooksonia cambrensis
Cooksonia downtonensis
Cooksonia rusanovii

以下四个物种现时已被置入其他属之下或已废弃。

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

参考文献

^ ^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

外部链接

[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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