A new rhyniopsid with novel sporangium organization from the Lower Devonian of South Wales
A new rhyniopsid with novel sporangium organization from the Lower Devonian of South Wales
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南威尔士下泥盆统具有新颖孢子囊组织的新菱藻类
DOI：
10.1111/j.1095-8339.1989.tb01713.x
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发表时间：
1989
影响因子：
2.4
通讯作者：
D. Edwards
中科院分区：
文献类型：
--
作者：
C. H. Shute;D. Edwards
本文对采自Gwent，S.威尔士表明，它们是喙孔类，在光滑的轴上有简单的等裂分枝，椭圆形的末端孢子囊长于宽，具有复杂的壁组织。因此，它们被归入一个新属。孢子囊壁有几个细胞厚，最外层的垂周壁和外周壁明显增厚，被平行于椭圆形器官最长尺寸的薄壁细胞区中断，并被认为与其裂成两个相等的一半有关。暗等孢子有双层壁，外层被认为是透明的周孢子。在孢子附近的片层和小球上以及孢子囊壁的最内表面上所见的类似的颗粒装饰物可能证明了周质团绒毡层的活动。过矿化的孢子囊被认为与那些具有椭圆形轮廓和明显边界的挤压化石中的孢子囊是同种的。对一些志留纪和泥盆纪早期化石中的开裂机制进行比较后发现，沿着最长的维度沿着分裂成两个相等的瓣，从而使最大面积的孢子暴露在大气中，这一现象在许多不相关的植物中独立出现。
Re-investigation of permineralized plants originally called Cooksonia sp. from the Lower Old Red Sandstone (Siegenian) of Gwent, S. Wales shows them to be rhyniopsids with simple isotomous branching in smooth axes and ellipsoidal terminal sporangia that are longer than wide and that possess a complex wall organization. They are thus placed in a new genus. The sporangial wall is several cells thick, the outermost comprising a layer with pronounced thickening of the anticlinal and outer periclinal walls, which is interrupted by a zone of thinner-walled cells parallel to the longest dimension of the ellipsoidal organ and considered to be involved in its dehiscence into two equal halves. The alete isospores have a bilayered wall, the outer interpreted as an ornamented perispore. Similar granular ornament seen on sheets and globules in the vicinity of the spores and on the innermost surface of the sporangium wall possibly demonstrates the activity of a periplasmodial tapetum. The permineralized sporangia are considered conspecific with those in compression fossils with elliptical outlines and pronounced borders. Comparison of presumed dehiscence mechanisms in a number of Silurian and early Devonian fossils suggests that splitting into two equal valves along the longest dimension, so that a maximum area of spores was exposed to the atmosphere, arose independently in a number of unrelated plants.
DOI：
10.1111/j.1095-8339.1986.tb01020.x
发表时间：
1986-09-01
影响因子：
2.4
作者：
EDWARDS, DS
通讯作者：
EDWARDS, DS