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

这项研究是建立热带西大西洋6-1 Ma间浅海海底群落区域对比和环境解释所需的年代地层格架的重要第一步。这项研究为评估动物群周转和群落变化提供了一个地层学和环境框架。它涉及的问题包括：(1)在影响现代加勒比海珊瑚礁生态系统发展的一段更替期间，珊瑚礁群落是否/如何随时间变化，以及(2)这些变化是否/如何与环境变化有关。正在结合关于海底有孔虫的新数据和关于沉积特征的信息来解释沉积环境。由此产生的地层和环境框架被用来评估珊瑚礁和自由生活珊瑚群落的时间和空间变化模式及其环境相关性。该项目还探索了群落变化、物种形成和灭绝之间的关系，以更好地了解随着新物种加入群落和灭绝物种被移除所涉及的生态过程。随着中美洲地峡的关闭和北半球冰川的开始，该地区的浅水海洋底栖群落因生物更替而发生了深刻的变化。分类组成和群落结构的变化在珊瑚和软体动物以及许多其他海洋生物中都有很好的记录。这些事件塑造了加勒比地区现代浅水底栖动物群落的组成和结构。更替的原因存在争议，人们对此知之甚少，部分原因是大多数进化研究不是在严格的地层和环境框架内进行的。需要高分辨率年代地层学来确定演化事件的时间，并重建影响营养物质和温度等环境因素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种之一的分类学，该种在更替结束时在加勒比海灭绝。通过将新的数据类型添加到爱荷华大学的新近纪热带美洲(NMITA)分类数据库，并将NMITA与时序联系起来，该项目为古生物界提供了信息。具体地说，该团队正在为一个经典的富含化石的层序开发一个综合的年代地层学模型，该层序从多米尼加共和国北部的慈宝山谷延伸到约6-3 Ma。该序列比任何其他已知的加勒比序列包含更多的珊瑚礁首次出现(91个记录物种中有37个是首次出现的)，因此对于理解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.