摘要
本文研究陕西中三叠世二马营组底部所产一种脊囊属(Annalepis Fliche)石松植物的原位(in situ)大孢子和散布于其围岩中的分散(dispersal)大孢子。两者显示连续的大孢子变化系列。据此,作者提出了该植物大孢子的主要发育阶段,并解释了化石石松植物大孢子多型性的原因:不仅与大孢子自身的发育正常与否以及其保存状态有关,更重要的在于大孢子不同发育阶段上的变化。
Structural details of the megaspores both in situ,preserved within one kind of spore-bear- ing organs previously assigned to Annalepis zeilleri Fliche,and in dispersal,found from the same matrix as these plant remains preserved in,have been investigated based on the fossil specimens from one bed in the bottom of the mid-Triassic Ermayin Formation at only one locality in Wupuxian district of Shaanxi Province,China.A continuous succession in mor- phological and structural changes of the megaspores has been obtained and as a result,a series of megasporegennic stages might be preliminarily elacidated as follows:the immature “nexine”stage,the mature Dijkstraisporites stage,the germinating Banksisporites stage when the sporodermis loosing after the megaspore had detached.In addition,Laevigatisporites-type megaspore may be abortive.
基金
国家自然科学基金
关键词
脊囊属
石松
大孢子
陕西
Shaanxi
Mid-Triassic
Annalepis
Megaspore
