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：晚寒武世三叶虫灭绝事件中的多样性和动物群更替模式：地层、环境和系统发育偏见的测试俄克拉荷马州耳机-0309092乔纳森·阿德雷恩，大学古生物学的最大挑战之一是了解化石记录中的大规模灭绝--生态系统崩溃和生物群灭绝的地质短暂时期。古生物学家越来越意识到，与物理过程或化石分类错误有关的各种偏见可能会扭曲灭绝的模式，甚至会在根本不存在的情况下制造灭绝的错觉。例如，海平面的变化通过侵蚀或不保存岩石记录关键区间的化石来影响我们对物种灭绝事件的看法。我们必须消除这种偏见，才能准确估计物种灭绝的规模，并评估可能导致灭绝的过程。这个项目评估了寒武纪三叶虫的记录中的偏见，并检查了潜在的灭绝机制。三叶虫是一群节肢动物，大约5亿年前是海洋环境中的优势动物。这些结果可能会为其他大灭绝事件带来新的曙光，特别是通过提供更好的理解各种偏见对我们认识此类事件的影响。通过俄克拉荷马大学和爱荷华大学的研究生参与，该项目还具有重要的教育组成部分。

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.