Collaborative Research: Patterns of Diversity and Faunal Turnover at a Late Cambrian Trilobite Extinction Event: Testing for Phylogenetic, Stratigraphic and Environmental Biases

合作研究：晚寒武纪三叶虫灭绝事件中多样性和动物区系更替的模式：地层、环境和系统发育偏差的检验Stephen Westrop，俄克拉荷马州大学-0309092 Jonathan Adrain，爱荷华州大学-0308685摘要古生物学的一个巨大挑战是理解化石记录中的大规模灭绝--在地质学上，生态系统崩溃和生物灭绝的短暂事件。 古生物学家越来越意识到，与物理过程有关的各种偏见或化石分类中的错误可能会扭曲灭绝模式，甚至在根本不存在灭绝的情况下制造灭绝的假象。 例如，海平面的变化通过岩石记录的关键间隔中的化石的侵蚀或不保存来影响我们对灭绝事件的感知。 在我们能够准确估计灭绝的规模并评估可能负责的过程之前，必须消除这些偏见。 该项目评估了寒武纪三叶虫记录中的偏见并研究了潜在的灭绝机制，这是一组节肢动物，大约5亿年前是海洋环境中的主要动物。 这些结果可能会为其他大规模灭绝事件提供新的线索，特别是通过更好地理解各种偏见对我们识别此类事件的影响。 通过俄克拉荷马州和爱荷华州大学研究生的参与，该项目还具有重要的教育内容。

Collaborative Research: Patterns of diversity and faunal turnover at a Late Cambrian trilobite extinction event: testing for stratigraphic, environmental and phylogenetic biasesStephen Westrop, Univ. Oklahoma EAR-0309092Jonathan Adrain, Univ. Iowa EAR-0308685ABSTRACTOne of the great challenges of paleontology is to understand mass extinctions in the fossil record - geologically brief episodes in which ecosystems collapsed and biotas were decimated. Paleontologists are becoming increasingly aware that various biases related to physical processes or errors in the classification of fossils can distort the pattern of extinction, or even create the illusion of extinction where none exists. For example, sea level changes influence our perception of extinction events through erosion or non-preservation of fossils in critical intervals of the rock record. Such biases must be stripped away before we can get an accurate estimate of the magnitude of extinction and assess the processes that might be responsible. This project evaluates biases and examines potential extinction mechanisms in the record of Cambrian trilobites, a group of arthropods that were among the dominant animals in marine environments about half-a-billion years ago. The results are likely to throw new light on other mass extinction events, particularly by providing a better understanding of the impact of various biases on our recognition of such events. The project also has a significant educational component through the participation of graduate students at the University of Oklahoma and the University of Iowa.