Paleobiological Patterns in Species Extinction, Survivorshipand Evolution across the K/T Boundary

该项目涉及当前生物地层学和古生物学研究的三个主要目标。1.跨越K/T界线的物种灭绝的性质：白垩纪末期的大规模灭绝事件在地质学上是渐进的还是突然的？物种灭绝对某些物种的选择性有多大？2.物种生存：浮游生物在多大程度上有孔虫在白垩纪末期的大规模灭绝事件中幸存下来？某些形态受到青睐吗？通才和专家，哪个物种更受青睐？他们活了多久？幸存物种是否产生了新的第三纪物种？3.物种灭绝后的辐射：物种多样性在大灭绝事件后如何反弹？多样化的速度是多少，是在灭绝事件发生后立即很高，还是有很大的滞后？什么样的分类学群体，通才或专家，对物种数量和个体相对丰富度的多样化做出了贡献？多样化是否与气候或生产力等环境因素相关？%此项目将审查陆地和海洋部分6500万年白垩纪/第三纪界线上的有孔虫大规模灭绝和随后的辐射的证据。将测量灭绝和辐射的速度，并检查物种形态和生态对这些速度的作用。将对灭绝后的辐射进行检查，以了解哪些物种幸存下来，以及它们随后的多样化是如何发生的。我们将研究气候和生产力在不同物种生存中的作用。这项研究的结果将提供地质记录中最著名的物种灭绝周围事件的详细图景。

This project addresses three major objectives in current biostratigraphical and paleobiological research. 1. THE NATURE OF SPECIES EXTINCTIONS ACROSS THE K/T BOUNDARY: To what extent was the end-Cretaceous mass extinction event gradual or sudden in geological terms? To what degree was extinction selective towards certain groups of species? 2. SPECIES SURVIVORSHIP: To what extent did planktic foraminifera survive the end-Cretaceous mass extinction event? Were certain morphologies favored? Which species were more favored, generalists or specialists? How long did they survive? Did surviving species give rise to new Tertiary species? 3. POST-EXTINCTION-EVENT RADIATION: How does species diversity rebound after a mass extinction event? What are the rates of diversification, are they high immediately after the extinction event, or are there substantial lags? What taxonomic groups, generalists or specialists, contribute to diversification in both numbers of species and relative abundance of individuals? Does the diversification correlate with environmental factors such as climate or productivity? %%% This project will examine the evidence for a mass extinction and subsequent radiation of foraminifera across the Cretaceous/Tertiary boundary at 65 million years in both land and marine sections. The rate of extinction and radiation will be measured and the role of species morphology and ecology on those rates will be examined. The post-extinction radiation will be examined to see which species survived and how their subsequent diversification occurred. The role of climate and productivity in the survivorship of different species will be examined. The results of this study will provide a detailed picture of the events surrounding the most well known extinction in the geologic record.