摘要
本文报道了滇东南文山地区下泥盆统坡松冲组(西根阶)地层中一陆生植物新属、种——曲轴古木蕨(Gumuia zyzzata gen.et sp.nov.)。植物矮小,匍匐或直立生长,二叉分枝。能育轴上孢子囊侧出,居于顶端或侧部位置,后者呈亚对生、交互对生或互生在曲折能育轴的折点上。孢子囊圆至横椭圆形,无柄或极短柄,成熟时通常切线垂直茎轴着生,并沿远端开裂。在系统分类上,依据新植物孢子囊侧出的性状,它暂被归人工蕨类,这有待于解剖结构的进一步证实。文中还对合轴分枝这一重要性状的发生做了探讨。
A new genus and species,Gumuia zyzzata is found in the Posonchong Formation of the Lo- wer Devonian (Siegenian) from Wenshan district of Yunnan,China.It has both lateral and terminal sporangia.Successive sporangia develop on alternate sides of short axes near the ha- ses of preceding sporangia,producing a zigzag fertile organization.The author supposes that it is a sympodium.Opposite sporangia are suppositionally referred to the result from condensation of the axis between alternate sporangia.The new plant is tentatively referred to a putative zosterophyll.
关键词
古木蕨
早泥盆世
西根期
Lower Devonian
Siegenian
Gumuia gen.nov.
Sympodium
