Paleobiology and Taphonomy of Lower Cambrian Burgess Shale-Type Deposits of Nevada and Greenland

摘要本文研究了内华达州西部和格陵兰岛北部两个早寒武世伯吉斯页岩型生物的古生物学和地学（死后历史）。这两个生物群都来自劳伦森（北美-格陵兰）古大陆，代表了世界上已知最古老的两个保存完好的动物群落。这些组合部分重叠了寒武纪多细胞动物适应性辐射的时间。它们为了解早寒武纪的进化史提供了重要的“窗口”，而且它们应该提供有关特殊保存发生的条件的信息。这项工作的主要目的是：1、收集和记录内华达新地点的生物区系，并继续记录格陵兰地点的生物区系；2、记录和解释有关内华达州和格陵兰岛遗址的地学信息；3、对与尸体化石相关的痕迹化石进行描述和解释；4、描述和解释内华达州和格陵兰岛遗址特殊保存的地层和沉积学背景；5 .确定早寒武纪生物群中存在的非矿化生物的生物地理亲缘关系。这项工作的完成将为了解早寒武纪末期灭绝前北美-格陵兰古大陆的生物多样性提供重要信息。这将为与Gondwanan地区早寒武世生物区系和Laurentia地区中寒武世生物区系的比较提供有力的生物地理基础。

ABSTRACTPALEOBIOLOGY AND TAPHONOMY OF LOWER CAMBRIAN BURGESS SHALE-TYPE DEPOSITS OF NEVADA AND GREENLANDLoren E. BabcockEAR-0106883This study involves the paleobiology and taphonomy (postmortem history) of two Early Cambrian Burgess Shale-type biotas from western Nevada and North Greenland. The biotas, both from the Laurentian (North America-Greenland) paleocontinent, represent two of the oldest known assemblages of exceptionally preserved animals in the world. These assemblages overlap in part the time of the Cambrian adaptive radiation of multicellular animals. They provide important "windows" into the evolutionary history of the Early Cambrian, and they should provide information about the conditions under which exceptional preservation occurred. The primary purposes of this work are: 1, to collect and document the biota of the new Nevada site and continue documentation of the biota of the Greenland site; 2, to document and interpret information about the taphonomy of the Nevada and Greenland sites; 3, to describe and interpret trace fossils associated with the body fossils; 4, to describe and interpret the stratigraphic and sedimentologic context of exceptional preservation in the Nevada and Greenland sites; and 5, to determine the biogeographic affinities of nonmineralized organisms present in the Early Cambrian biotas. Completion of this work will provide important information about biologic diversity on the North America-Greenland paleocontinent prior to the terminal Early Cambrian extinction. This, in turn, is expected to provide a strong basis for biogeographic comparison with Early Cambrian biotas of Gondwanan areas, and a basis for comparison with biotas from the Middle Cambrian of Laurentia.