Collaborative Research: Associations between climate shifts and ammonoid turnover across second-tier extinctions during the early Late Cretaceous greenhouse

随着气候变化，准确预测环境变化将如何影响海洋动物，以协助保护生物学工作，这将是非常重要的。像鱿鱼和章鱼这样的鲸类在生态上是重要的，既是捕食者也是猎物，对美国渔业也是重要的经济来源。这个项目将调查现代鱿鱼和章鱼的化石亲属--菊石的进化和灭绝模式。在9000万到1亿年前，地球经历了多次冷却和变暖。通过调查帮助一些菊石物种在这些事件中幸存下来的特征，该项目将确定控制头足类动物灭绝风险的关键因素。该项目还将包括对两所大学的本科生和研究生进行培训，为公开的数据库以及基于计算机和互联网的研究工具做出贡献，并为儿童和公众编写关于气候变化如何影响海洋动物和生态系统的教育材料。冷和海平面福尔斯下降，在中期森诺曼和中期Turonian和变暖，广泛缺氧，海平面上升，在最后的森诺曼和最早的Turonian。该项目将包括使用贝叶斯系统发育分析和ecomorphospace分析的菊石头足类超科pameroceratoidea梳理除了这些环境扰动影响acanthoceratoid多样性动态的程度作为一个整体，以及这些扰动如何影响不同的形态与不同的基本菊石生态习性。该项目团队将测试与这三个事件中的每一个事件的系统发育和生态形态选择性相关的假设，并评估跨角鲨总科的替代灭绝和起源模型。系统发育分析代表了第一次使用贝叶斯系统发育方法菊石，也有助于通过贝叶斯方法同时评估宏观进化模型和系统发育关系的进步。因此，最终结果将提供有关特定气候变化如何影响菊石灭绝率的信息，并为在地球系统演化的其他关键时期对其他分类群进行类似评估提供模型。最终，拟议的研究将确定驱动多样性动态和中层捕食者灭绝风险的关键因素，这是一个重要但经常被忽视的海洋生态guild.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

As climate changes, it will be important to accurately predict how environmental shifts will impact marine animals in order to assist conservation biology efforts. Cephalopods like squid and octopus are ecologically important, as both predator and prey, and economically important for the U.S. fisheries industry. This project will investigate patterns of evolution and extinction in fossil relatives of modern squid and octopus, the ammonoids. Between 90 and 100 million years ago, Earth experienced multiple episodes of cooling and warming. By investigating the traits that helped some ammonoid species survive these events, the project will identify key factors that control extinction risk in cephalopods. The project will also include training for undergraduate and graduate students at two universities, contribute to publicly available databases and computer- and internet-based research tools, and develop educational materials for children and the general public on how climate change affects marine animals and ecosystems.The Cenomanian-Turonian interval of the early Late Cretaceous witnessed three substantial climate shifts, cooling and sea level falls in the middle Cenomanian and middle Turonian and warming, widespread anoxia, and elevated sea level over the latest Cenomanian and earliest Turonian. This project will include the use of both Bayesian phylogenetic analyses and ecomorphospace analyses of the ammonoid cephalopod superfamily Acanthoceratoidea to tease apart the extent to which these environmental perturbations affected acanthoceratoid diversity dynamics as a whole and how those perturbations affected different morphotypes associated with different basic ammonoid ecological habits. The project team will test hypotheses related to phylogenetic and ecomorphological selectivity across each of these three events and assess alternative extinction and origination models across Acanthoceratoidea. The phylogenetic analyses represent the first use of Bayesian phylogenetic methods for ammonoids and also contribute to advancements for simultaneously assessing macroevolutionary models and phylogenetic relationships via Bayesian methods. Thus, the final results will both be informative about how particular climate shifts affected ammonoid extinction rates and provide a model for similar assessments of other taxonomic groups during other critical intervals of Earth system evolution. Ultimately, the proposed research will identify key factors that drive diversity dynamics and extinction risk for mid-level predators, an important but often overlooked marine ecologic guild.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.