Gemellitheca gen. nov., a fertile pecopterid fern from the Upper Permian of the Middle East
Gemellitheca gen. nov., a fertile pecopterid fern from the Upper Permian of the Middle East
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发表时间：
1985
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通讯作者：
R. Wagner;C. R. Hill;A. A. El-Khayal-A.
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作者：
R. Wagner;C. R. Hill;A. A. El-Khayal-A.
具典型双室合囊的盾叶蕨科植物，沙特盾叶蕨Gemellitheca saudica gen. et sp. nov.，在沙特阿拉伯的Unayzah植物床和土耳其东南部Hazro inlier的Gomaniimbrik组中描述。合囊附着于小羽片边缘，延伸至整个或几乎整个小羽片的半宽。最接近的比较是Dizeugotheca Archangelsky & de la Sota，这是一种二叠纪的胸鳍类，其果实横置，看起来非常相似，但Dizeugotheca被描述为具有孢子囊群，孢子囊群以四个为一组，每组中的两个与其他两个大部分重叠。合囊体有3 ~ 4个室，但很少见于双囊壳（Gemellitheca saudica）。双石松属的亲缘关系被认为与马拉蒂亚蕨类植物有关。它的一些特征与Scolecopteris Zenker的物种相同。
Pecopterid fronds bearing typically bilocular synangia, Gemellitheca saudica gen. et sp. nov., are described from the Unayzah plant bed in Saudi Arabia and the Gomaniimbrik Formation of the Hazro inlier in southeastern Turkey. The synangia are attached near the sharply incurved pinnule margin and extend across the whole or almost the whole half-width of the pinnules. Their apices lie near and in some cases over the midrib, and are curved abaxially away from it. The closest comparison is with Dizeugotheca Archangelsky & de la Sota, a Permian pecopterid with transversely placed fructifications which look very similar, but Dizeugotheca is described as having sori with sporangia consistently in groups of four, two of each group being largely overlapped by the other two. Synangia with three or four locules occur in Gemellitheca saudica but are rare. The affinities of Gemellitheca are considered to lie with the marattialean ferns. A number of its characters are shared with species of Scolecopteris Zenker.