摘要
宽背虫(Bathynotus)这一传统早寒武世或寒武纪第2世晚期最重要的三叶虫属,广泛分布于全球寒武纪3个生物大区,为区域地层对比的标准化石。Bathynotus在贵州剑河八郎乌溜-曾家崖剖面凯里组下部极为丰富。该剖面已成为全球寒武系第2统和第3统界线层型候选剖面,表明凯里组是一个穿时的地层单元,其3个三叶虫带最下部一个带为Bathynotus holopygus-Ovatoryctocara granulata.经过逐层大量的化石标本采集统计证实,乌溜-曾家崖剖面宽背虫(Bathynotus)在距凯里组底部51.60 m处骤然绝灭,距寒武系第2统的顶界(距凯里组底52.80 m)只有1.20 m.本文就乌溜-曾家崖剖面凯里组下部宽背虫(Bathynotus)的数量分布变化认为其灭绝过程是逐步的。
Bathynotus is the most important trilobite genus as the late Cambrian 2 series. It is widely distributed in three realms of Cambrian in the world and has very important significance for subdivision of Cambrian stratigraphy in the world. Bathynotus from Kaili Formation at Wuliu - Zengjiaya Section Balang Village,Jianhe County,Guizhou Province are extremely rich and preserved a complete sequence of ontogeny. After specimens from a stratigraphical interval exammed, we confirm that Bathynotus was extinct suddenly on position of 51.60 m away from the base of Kaili Formation, at Wuliu - Zengjiaya Section. This position is only 1.20 m upward to the top of Cambrian 2 Series （that is, 52.80 m away from the base of Kaili Formation）. Here, we attempts to understand the process of extinction of Bathynotus of the lower part of Kaili Formation by methods of mathematic statistics for specimens collecting continuously little layers and fossil sequence change analysis. This research indicates the process of extinction is a gradual change, that is, Bathnotus distributed at Wuliu - Zengjiaya Section, close to the extinct position only were found mature no juvenile specimens.
出处
《贵州工业大学学报（自然科学版）》
CAS
2008年第1期6-11,共6页
Journal of Guizhou University of Technology(Natural Science Edition)
基金
国家973重大项目(2006CB806401)
贵州省科技特别基金(黔科机字20074004)
