青岩螺旋蟲（“Spirorbis” qingyani Stiller, 2000）是採集於貴陽市花溪區青岩鎮的化石標本。
基本介紹
- 中文名：青岩螺旋蟲
- 外文名：“Spirorbis” qingyani Stiller, 2000
- 產地：貴陽市花溪區青岩鎮
- 保存單位： 中國科學院南京地質古生物研究所
特徵描述,主要用途,
特徵描述
small,solitary spirobid with calcareous shell of up to three whorls sinistrally coiled in a flat spiral.diameter of tube rapidly and regularly increasing,last whorl almost fully enveloping inner ones;deep umbilicus very narrow;broad base of tube cemented to substrate in its entire length;outer tube surface convex,umbilical part steeply sloping;tube with ovally three-sided cross section,lumen oval;tube slithtly narrowing near aperture in adults;outer surface of tube smooth,only weak growth lines distinctly bent adapically on outer part of surface;aperture bulging correspondingly;at margin of umbilicus sometimes weak wrinkles;tube wall rather thin,consisting of two layers;outer,darker layer much thicker than thin,light inner one.
主要用途
地層劃分與對比。
