Early evolution of trophic disparity in Pachycormidae (Actinopterygii)

厚脉科（Actinopterygii）营养差异的早期进化

• 批准号: 507867847
• 负责人: Dr. Erin Maxwell
• 金额: --
• 依托单位: Abteilung Paläontologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/507867847?language=en
• 关键词: Early; evolution; trophic; disparity; Pachycormidae

Pachycormidae is a lineage of bony fishes best known for the evolution of gigantic suspension feeders, but also comprising small- to mid-sized fish- and squid-eating species. First recorded from the Early Jurassic of Europe, pachycormids are characterized by diversity in body shape, size, and diet, with analyses recovering two key evolutionary radiations: a group comprising the giant suspension-feeders, and a macrocarnivorous (‘toothed’) lineage. The proposed project aims to examine the generation of species and ecological (dietary) diversity early in the evolutionary history of Pachycormidae. The proposed project will seek to answer the following question: Is the early burst of species-level diversity in Pachycormidae associated with concomitant dietary diversity? The question will be addressed from two complementary angles. (1) An ecological perspective (a detailed study of dietary divergence in the earliest pachycormids); and (2) an evolutionary perspective (diversity in tooth- and jaw shape over deep time in an explicitly evolutionary context). The combination of these two perspectives will address the relationship between diversity in species and diet over both geologically short and long timescales to give a refined picture of the scale on which the results apply. Pachycormids are already rather diverse by their first appear in the fossil record, in the Early Jurassic Posidonienschiefer Formation of Germany. However, dietary divergence in these early forms is less well-characterized, and at the most basic level, the relationship between tooth- and jaw morphology and dietary ecology has not been robustly demonstrated. The first project objective will be to test the assumption that morphology relates to diet by comparing shape with preserved gastrointestinal contents. Secondly, the project will address how variation in tooth and jaw shape changes over a geologically short interval by analyzing diversity in shape. This will be executed at the specimen level, to minimize potentially confounding influences of shape and dietary variation within species vs. between species. The project will go on to examine the evolutionary implications of the relationship between anatomy and diet. To do so will involve the generation of a robust species-level phylogenetic hypothesis for Pachycormidae. This more detailed phylogenetic hypothesis will provide a framework with which to analyze evolutionary rates and evolutionary divergence in tooth and jaw shape over time in Pachycormidae. The objective is to test whether rates of morphological evolution are highest early in the history of the group, and to assess whether ecomorphological divergence follows a similarly explosive trajectory or increases gradually over time.

厚科是硬骨鱼类的一个分支，以其巨大的悬浮食性而闻名，但也包括中小型鱼类和鱿鱼类。最早记录于早侏罗世的欧洲，厚蛾的特点是身体形状、大小和饮食的多样性，分析恢复了两个关键的进化辐射：一个由巨型悬浮食性动物组成的群体，以及一个大型食肉动物（“有牙齿”）的谱系。本项目旨在研究厚蛾科植物在进化早期的物种产生和生态（饮食）多样性。拟议的项目将寻求回答以下问题：厚绒科物种水平多样性的早期爆发是否与伴随的饮食多样性有关？这个问题将从两个互补的角度来解决。(1)生态学视角（详细研究最早厚蛾的饮食差异）；(2)进化观点（在明确的进化背景下，牙齿和下颌形状在较长时间内的多样性）。这两种观点的结合将在地质学的短期和长期时间尺度上解决物种多样性和饮食之间的关系，从而为结果适用的尺度提供一幅精细的图景。在德国早侏罗世Posidonienschiefer组的化石记录中，厚球虫的种类已经相当丰富了。然而，这些早期形式的饮食差异并没有得到很好的表征，而且在最基本的层面上，牙齿和颌骨形态与饮食生态之间的关系还没有得到有力的证明。第一个项目目标将是通过比较形状和保存的胃肠道内容物来检验形态学与饮食有关的假设。其次，该项目将通过分析形状的多样性来解决牙齿和颌骨形状在地质短间隔内的变化。这将在标本水平上执行，以尽量减少物种内与物种之间的形状和饮食变化的潜在混淆影响。该项目将继续研究解剖学和饮食之间关系的进化含义。要做到这一点，将涉及对厚孢子虫科产生一个强有力的物种水平的系统发育假说。这个更详细的系统发育假说将提供一个框架，用于分析长尾科动物牙齿和下颌形状随时间的进化速率和进化分歧。目的是测试形态进化的速率是否在类群历史的早期达到最高，并评估生态形态的分化是否遵循类似的爆炸性轨迹，还是随着时间的推移逐渐增加。