Collaborative Research: A Depositional and Paleoecological model of Neogene Reef Development in the Dominican Republic: Integrating Taxonomic and Chronostratigraphic Databases

本研究为构建6 ~ 1 Ma热带西大西洋浅海底栖生物群落区域对比和环境解释所需的年代地层框架迈出了重要的第一步。该研究为评价动物更替和群落变化提供了一个地层学和环境框架。它解决的问题包括：(1)在形成现代加勒比珊瑚礁生态系统发展的更替时期，珊瑚礁群落是否/如何随着时间的推移而变化，以及(2)这些变化是否/如何与环境变化相关。有关底栖有孔虫的新数据正在与沉积特征信息相结合，以解释沉积环境。由此产生的地层和环境框架用于评估礁珊瑚和自由生活珊瑚群落及其环境相关物的时空变化模式。该项目还探讨了群落变化、物种形成和灭绝之间的关系，以便更好地了解新物种加入群落和灭绝物种被移除时所涉及的生态过程。由于中美洲地峡的关闭和北半球冰川的开始，该地区的浅海底栖生物群落发生了深刻的变化。珊瑚、软体动物和许多其他海洋生物的分类组成和群落结构的变化都有很好的记录。这些事件塑造了加勒比地区现代浅层底栖生物群落的组成和结构。更替的原因是有争议的，人们对其知之甚少，部分原因是大多数进化研究都不是在严格的地层和环境框架下进行的。高分辨率年代地层学需要用于确定进化事件的时间，并用于重建影响环境因素（如营养和温度）的海洋环流和海平面的区域变化。作为这项工作的一部分，该小组正在修订最重要的生态优势之一的系统分类学，Stylophora在加勒比地区灭绝。该项目通过将新的数据类型添加到爱荷华大学的热带美洲新近纪海洋b(I)ota （NMITA）分类数据库中，并将NMITA与CHRONOS连接起来，为古生物学界提供信息。具体来说，该团队正在开发一个综合的年代地层模型，用于一个经典的，丰富的化石序列，从多米尼加共和国北部的Cibao山谷延伸到~6-3 Ma。该序列比其他已知的加勒比序列包含更多首次出现的珊瑚礁珊瑚（91个记录物种中有37个首次出现），因此对了解物种更替期间的物种形成事件至关重要。

This study represents an important first step in constructing the chronostratigraphic framework needed for regional correlation and environmental interpretation for shallow marine benthic communities in the tropical Western Atlantic between 6 and 1 Ma. The research provides a stratigraphic and environmental framework for evaluating faunal turnover and community change. It addresses questions including: (1) if/how did reef communities change over time during an episode of turnover which shaped the development of modern Caribbean reef ecosystems, and (2) if/how were these changes related to changes in the environment. New data on benthic foraminifera are being combined with information on sedimentary features to interpret depositional environments. The resulting stratigraphic and environmental framework is used to assess patterns of temporal and spatial variation in both reef coral and free-living coral communities and their environmental correlates. The project also explores the relationship between community change, speciation, and extinction in order to better understand the ecological processes involved as new species were added to communities and extinct species were removed.Shallow marine benthic communities in the area were profoundly altered by biotic turnover associated with the closure of the Central American isthmus and the onset of Northern hemisphere glaciation. Changes in taxonomic composition and community structure are well documented in corals and mollusks and in many other marine organisms. These events were responsible for shaping the composition and structure of modern-day shallow benthic communities in the Caribbean region. The causes of turnover are controversial and poorly understood, in part because most evolutionary studies are not performed within the context of a rigorous stratigraphic and environmental framework. High-resolution chronostratigraphy is needed for determining the timing of evolutionary events, and for reconstructing regional changes in ocean circulation and sea level that affected environmental factors such as nutrients and temperature. As part of this work, the group is revising the systematics of one of the most important ecological dominants, the Stylophora, which became extinct in the Caribbean at the end of the turnover.By adding new data types to the Neogene Marine b(I)ota of Tropical America (NMITA) taxonomic database at the University of Iowa and linking NMITA with CHRONOS, the project provides information to the paleontological community. Specifically, the team are developing an integrated chronostratigraphic model for a classic, richly fossiliferous sequence extending from ~6-3 Ma, the Cibao Valley of the northern Dominican Republic. The sequence contains more first occurrences of reef corals than any other known Caribbean sequence (37 of the 91 recorded species first occur) and is therefore critical for understanding speciation events during turnover.