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Morphological Evolution and Diversification in the Earliest Herbivorous Tetrapod

最早的草食性四足动物的形态进化和多样化

基本信息

批准号：
400025865
负责人：
Dr. Neil Brocklehurst
金额：
--
依托单位：
Department of Earth Sciences
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/400025865?language=en
关键词：
Morphological Evolution Diversification Earliest Herbivorous

项目摘要

The origin of herbivory in tetrapods (land vertebrates) during the Carboniferous was a crucial event in the establishment of terrestrial vertebrate ecosystems. Herbivory had evolved independently at least eight times by the end of the Paleozoic, and these convergent evolutionary origins provide an ideal case study for examining patterns of morphological evolution, convergence and partitioning during adaptive radiations. An adaptive radiation is the morphological diversification among ecologically-relevant traits that occurs when lineages exploit a new adaptive zone. The new adaptive zone may be created by: a “key innovation” allowing the clade to access previously unused resources; the appearance of a new resource; or the extinction of the previous occupants of the adaptive zone. Paleozoic herbivorous tetrapods provide an opportunity to study all three modes. Numerous morphological innovations are documented in the fossil record to allow exploitation of plant matter. Plants underwent several diversification and turnover events during the Carboniferous and Permian, potentially providing new material to be exploited. Finally, an extinction event dubbed Olson’s extinction at the end of the Kungurian stage provides an opportunity to study the radiation of new herbivorous lineages following a mass extinction. In this project, I aim to answer three questions: Are patterns of craniodental evolution in Paleozoic herbivores consistent with the predictions of adaptive radiation models? Do the independent, contemporaneous origins of herbivory show ecomorphological differentiation consistent with niche partitioning during adaptive radiations? Are patterns of morphological diversity and species richness in Paleozoic herbivores related to the diversification patterns of plants? These questions will be examined using a wide range of methods for quantifying evolution. Discrete character data will be examined using recently-proposed statistical methods to identify trends in morphological diversity variation in rates of character change. Paleozoic herbivore skulls will be landmarked to quantify skull shape, and this shape data will be used to assess morphological overlap between the different clades of Paleozoic herbivores. Species-richness estimates both of herbivores and plants, corrected for incomplete sampling, will be compared to identify interactions between the two. This research aims to greatly improve our understanding, not only of the critical period in the establishment of terrestrial ecosystems, but also the mechanisms underlying adaptive radiations.

石炭纪四足动物（陆生脊椎动物）草食性的起源是陆生脊椎动物生态系统建立的关键事件。到古生代末，食草动物已经独立进化了至少8次，这些趋同的进化起源为研究适应性辐射过程中形态进化、趋同和分割的模式提供了理想的案例研究。适应性辐射是当谱系利用新的适应区时发生的生态相关性状之间的形态多样性。新的适应区可以通过以下方式创建：允许进化枝访问先前未使用的资源的“关键创新”;新资源的出现;或适应区的先前占用者的消失。古生代草食性四足动物提供了一个机会，研究所有三种模式。化石记录中记载了许多形态学上的创新，从而可以利用植物物质。在石炭纪和二叠纪，植物经历了几次多样化和周转事件，可能提供新的材料进行开发。最后，在昆古阶末期发生的一次被称为奥尔森灭绝的灭绝事件为研究大灭绝后新的食草动物谱系的辐射提供了机会。在这个项目中，我的目标是回答三个问题：在古生代食草动物的颅齿演化模式与适应性辐射模型的预测一致吗？独立的，同时期的起源草食动物表现出生态形态分化与生态位划分在适应辐射？古生代食草动物的形态多样性和物种丰富度模式与植物多样性模式有关吗？这些问题将使用各种量化进化的方法进行研究。离散字符数据将使用最近提出的统计方法，以确定字符变化率的形态多样性变化的趋势进行检查。古生代食草动物头骨将被标记为量化头骨形状，这种形状数据将被用来评估古生代食草动物不同分支之间的形态重叠。物种丰富度估计的食草动物和植物，校正不完整的采样，将进行比较，以确定两者之间的相互作用。这项研究的目的是大大提高我们的理解，不仅在建立陆地生态系统的关键时期，而且适应性辐射的机制。