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通过对采自湖南益阳南坝剖面的Acrograptus标本的研究,本文对该属作了如下厘定:笔石体两枝近水平至下斜伸展,胎管长且纤细;th11从亚胎管始部生出,th12为双芽胞管,始端发育型式为等称笔石型(isograptid);th11和th12在不同水平位置弯离胎管,导致始端部分不对称;th12与th21的原胞管部分极为纤细,构成两个细弱的横管.经厘定后,Acrograptus归入均分笔石科、弯笔石亚科,共包含6个种:A.affinis(Nicholson),A.filiformis(Tullberg),A.gracilis(Trnquist),A.nicholsoni(Lapworth),A.pusillus(Tullberg)以及A.saukros(Ni).这6个种在华南广泛分布,其中在上扬子区和江南区中东部较为集中.进一步研究表明,在华南,最早的Acrograptus于弗洛初期出现在水体较深的斜坡相区.弗洛期Pendeograptus fruticosus带初,该属经历了一次明显的扩散事件,属内各种由斜坡向较浅水的台地迁移.这一扩散事件可能直接受控于弗洛中期一次大规模的海侵事件.
Based on the study of Acrograptus collected from the Nanba section of Yiyang, Hunan Province, this paper determined the genus as follows: two branches of penoliths were nearly horizontal to obliquely stretched, the tube was long and slender; th11 was born from the beginning of the tube , th12 is a double-spore tube, the beginning of the development type is called isograptid; th11 and th12 bent at different levels away from the fetal tube, leading to the beginning part of the asymmetric; th12 and th21 of the original cell tube is very thin, Acrograptus is divided into two groups: Pinaceae and Pinaceae, with six species: A.affinis (Nicholson), A.filiformis (Tullberg), A..gracilis (Trnquist) , A. nicholsoni (Lapworth), A.pusillus (Tullberg) and A.saukros (Ni). These six species are widely distributed in South China, and are more concentrated in the upper Yangtze region and the middle and eastern part of Jiangnan District.Further studies show that in South China , The earliest Acrograptus appeared in the deeper slope facies of the water body in the early period of Flo.From the early stage of the Pendeograptus fruticosus, the genus experienced a significant spreading event, belonging to various kinds of slope-to-shallow terraces. A proliferation event may be directly controlled by the mid-term Florian Transgressive event.