Collaborative Research: Foreland basin development and biotic change in Late Ordovician trilobite faunas of eastern North America

本项目侧重于在区域到大陆范围内重构生态系统的小灭绝，以及相对生态稳定性的通常间断间隔。这些地质上频繁的灭绝事件对生物圈的累积影响可能超过了众所周知的、相对罕见的全球大灭绝的影响。这种小规模的灭绝也令人感兴趣，因为它们在规模上可能更接近威胁现代生物群的许多人为栖息地改变过程。pi将研究北美东部晚奥陶世三叶虫动物群的两期生物更替，这是对Taconic造山运动期间与阿巴拉契亚前陆盆地发展相关的深刻环境变化的响应。他们将使用比较的方法来发现这两个事件的共同特征。较年轻的事件发生在晚伊登世-梅斯维尔世，其特征是三叶虫生物相的入侵，以奥棱世为主，三叶虫生物相可能是区域性古海洋学变化的生物特征，与构造相关的盆地结构和/或海游变化有关。其他环境变化表现在更古老的事件(图里尼？在浅水环境中出现了隐石三叶虫，这是一组通常出现在较深环境中的三叶虫。肯塔基州前陆盆地的两条横断面？田纳西?弗吉尼亚和纽约中部？在安大略省南部，将包括在研究中。俄克拉何马州中南部，阿巴拉契亚前陆盆地之外的地区，将被用作控制区。以帮助隔离该盆地特有的动物模式。将沉积岩演替资料与碳同位素曲线相结合进行环境重建。该项目包括对三叶虫动物群的系统学、生物地层学和古生态学的全面研究。拟议活动的更广泛影响在于教育和培训；四名研究生和至少四名本科生将参与研究。ppi还将通过制定一项新的物种灭绝研究计划，为公众带来更广泛的灭绝研究影响。虚拟展览?以及与俄克拉何马州自然历史博物馆教育部合作的其他基于网络的教育资源。他们不仅会考虑灭绝？深的时间吗?以及最近的过去（第四纪灭绝）和生物圈目前面临的挑战（如全球气候变化、海洋酸化和栖息地破坏等问题）。

ABSTRACT This project focuses on the minor extinctions that restructure ecosystems on regional to continent-wide scales and commonly punctuate intervals of relative ecological stability. These geologically frequent extinction events may have a cumulative effect on the biosphere that exceeds the impact of the better-known, relatively rare global mass extinctions. Such minor extinctions are also of interest because they may be closer in scale to many of the processes of anthropogenic habitat alteration that threaten the modern biota. PIs will study two episodes of biotic turnover in the Late Ordovician trilobite faunas of eastern North America that are responses to profound environmental changes associated with the development of the Appalachian Foreland Basin during the Taconic Orogeny. They will use a comparative approach to discover features common to both events. The younger event, in the late Edenian-Maysvillian is characterized by incursions of trilobite biofacies dominated by the oleniodean, Triarthrus that may be the biotic signatures of regional paleoceanographic shifts associated with tectonically-related changes in basin configuration and/or eustasy. Other environmental changes are expressed at the older event (Turinian?Chatfieldian boundary interval) by the appearance in shallow water settings of cryptolithine trilobites, a group that typically occurs in deeper environments. Two transects into the foreland basin, Kentucky?Tennessee?Virginia and central New York?southern Ontario, will be included in the study. South-central Oklahoma, a region outside of the Appalachian foreland basin, will be used as a ?control? to help isolate faunal patterns that are unique to the basin. The environments will be reconstructed by combining data from the sedimentary rock succession with carbon isotope curves. The project includes a full treatment of the systematics, biostratigraphy and paleoecology of the trilobite faunas. The broader impact of the proposed activity lies in education and training; four graduate students and at least four undergraduates will participate in the study. PIs will also bring the broader implications of the study of extinctions to the public by developing a ?virtual exhibit? and other web-based educational resources in collaboration with the Education Department at the Oklahoma Museum of Natural History. They will consider not only extinctions in ?deep time?, but also the recent past (Quaternary extinctions) and the challenges currently facing the biosphere (such issues as global climate change, ocean acidification, and habitat destruction).