Integrated Biostratigraphic Standard of Reference for the Lower Devonian (Lochkovian) Using Conodonts and Graptolite Lineages

这项研究将继续进行研究，寻求在牙形刺和笔石谱系内变化的定量研究的基础上，为北美西部科迪勒拉的下泥盆统动物群建立一个综合的生物地层学参考标准，并将在合成过程中增加介形虫动物群。一个完整和详细的参考标准对于了解生物地理、生物相和演化模式的古生物学问题是必要的。它还需要解决需要高度分辨率的地层和构造问题。这样的研究在文献中很少见，因为成功所必需的因素同时出现的情况很少见。以前对内华达州中部下泥盆统的定量研究已经证明了为此目的进行牙形刺谱系统计研究的实用性。这些研究的副产品表明，一些额外的重要的下泥盆统牙形刺谱系全部或部分存在于它们的几个已知剖面或延伸中。这些剖面位于托基马山脉、辛普森公园山脉、莫尔摩尔山脉和罗伯茨山脉，构成了目前已知的该地区这部分柱状物的牙形刺和笔石生物地层学的主要数据库。对几个谱系的研究表明，可以达到的相关性得到了加强，这种研究在获得稳定的分类方面也是有用的。两者都是建立详细稳定的生物地层学参考标准所必需的成分。

The research will continue studies that seek to establish an integrated biostratigraphic standard of reference for Lower Devonian faunas of western North America Cordillera based on quantitative studies of variation within conodont and graptolite lineages and will add ostracode faunas to the synthesis. An integrated and detailed standard of reference is necessary to an understanding of paleobiological problems of biogeography, biofacies and patterns of evolution. It is also required to solve stratigraphic and structural problems requiring a high degree of resolution. Such studies are rare in the literature because the concurrence of the factors necessary for success is rarely encountered. Previous quantitative studies of the lower Lower Devonian in central Nevada have demonstrated the utility of conducting statistical studies of conodont lineages for this purpose. By-products of these studies indicate that a number of additional important Lower Devonian conodont lineages are present entirely or in part in several known sections or extensions of them. These sections are located in the Toquima Range, the Simpson Park Range, the Monitor Range and the Roberts Mountains and have formed the primary data base for what is presently known of conodont and graptolite biostratigraphy of this part of the column in the region. Study of several lineages has shown the enhancement of correlation that can be attained and the utility of such studies in attaining a stable classification. Both are ingredients necessary to a detailed and stable biostratigraphic standard of reference.