摘要
通过对广西六景地区谷闭组下部的牙形石Ancyrodella类群的早期个体分析 ,识别出Ancyrodellabino dosa→Ancyrodellarotundiloba→Ancyrodellaalata→Ancyrodellagigas的演化谱系。以中 上泥盆统界线层型剖面为准 ,由Ancyrodellarotundilobaearlyform的首次出现为标志 ,将六景地区中 上泥盆统界线置于谷闭组底界之上1 .80m处 ,这条处于Ancyrodella早期演化系中间的界线是一条可靠的和高分辨率的界线 。
Based on an analysis to the stratigraphical and morphological sequence of early species of conodont Ancyrodella from the lower part of the Gubi Formation at Liujing(Guangxi), the evolutionary lineage Ancyrodella binodosa→A. rotundiloba→A.alata→A.gigas has been recognized. By the correlation with the GSSP of the Middle Upper Devonian boundary, the Middle Upper Devonian boundary at Liujing defined by the first occurrence of Ancyrodella rotundiloba early form is placed at a level of 1.80m above the base of the Gubi Formation. This boundary within the early evolutionary lineage of Ancyrodella is reliable, and can be used in high resolution correlation with the GSSP.
出处
《古生物学报》
CAS
CSCD
北大核心
2000年第2期197-204,共8页
Acta Palaeontologica Sinica
