湖北宜昌黄花场早奥陶世生物礁中发现

FOUND IN EARLY ORDOVICIAN REEF AT HUANGHUACHANG, YICHANG, HUBEI

朱忠德 刘秉理 李相明

Zhu Zhongde Liu Bingli Li Xiangming

作者在湖北宜昌早奥陶世岩隆礁中发现了 ,这在国内以及亚洲地区尚属首例.Pul-chrilamina 产于下奥陶统分乡组礁岩段,是一种独特的纹层状生物,由纹层和针刺组成.据纹理的发育状况、晶粒的结晶程度,可分为晶粒纹层、灰泥纹层和似纹层三类.其中,晶粒纹层具镶嵌结构,可形成粘结孔.针刺垂直生长于纹层上层面,呈下粗上细渐变尖灭.针刺长度、间隔距离、长度与直径比等均不具相关关系.晶粒纹层、似纹层的针刺尖端一般不抵达上覆纹层底面,而灰泥纹层的针刺则相反.笔者倾向于将 暂时列入分类位置未定的门、纲、目之下的一个科,但据其形态,不排除隶属于某种藻类的可能性。在 岩隆礁中, 属于原地生长,就地保存,并以粘结方式建礁。

was found recently in Early Ordovician bioherm at Huanghuachang,Yichang,Hubei Province.This is the first time to find this fossil in China and even in Asia. is a unique laminal organism occurred in reef rock member of the Fengxiang Formation(O),and consists of laminae and spines.According to the develop-ment of laminae and the crystallographic degree,the laminae can be divided into crystal lamina,lime mud lamina and lamina-like,crystal lamina has mosaic texture and could form binding pores.Spinas grow erectly on the upper surface of the lamina and get thin-ner gradually like pin.The length,the distance and the ratio of the length to diameter is irregular.The spina ends of crystal laminae and lamina-like generally do not extend to the base of the overlying lamina,but it is opposite for lime mud lamina.It is suggested by theauthors to put temporarily under a family among incertitude(or uncertain)phylum,class,order.According to the 's configuration,it possibly belongs to a certain algae.In baffling buildup, is of the kind that is grown and preserved in situ and is built up by binding.

10.11743/ogg19930407