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（陆地脊椎动物）的食草起源是陆地脊椎动物生态系统建立的一个关键事件，到古生代末食草动物已经独立进化了至少八次，这些趋同进化起源提供了一个理想的研究案例。用于检查适应性辐射期间形态进化、收敛和分配的模式。适应性辐射是生态相关性状之间的形态多样化。当谱系利用新的适应区时，可能会通过以下方式创建：“关键创新”，允许进化枝访问以前未使用的资源；或适应区先前占用者的灭绝；古生代食草四足动物提供了研究所有三种模式的机会，化石记录中记录了许多形态创新，使植物在石炭纪和二叠纪期间发生了几次多样化和更新事件。最后，昆古阶末期被称为奥尔森灭绝的事件为研究大规模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：古生代食草动物的颅齿进化模式与适应性辐射模型的预测一致吗？独立的、同时代的食草动物起源是否表现出与适应性辐射期间的生态位划分一致的生态形态分化？与植物多样化模式相关的古生代食草动物的形态多样性和物种丰富度模式？将使用各种量化进化的方法来检查这些问题，以识别形态趋势。古生代食草动物头骨的特征变化率的多样性变化将被标记以量化头骨形状，并且该形状数据将用于评估古生代不同分支之间的形态重叠。食草动物和植物的物种丰富度估计（针对不完整的采样进行了校正）将进行比较，以确定两者之间的相互作用。这项研究不仅旨在大大提高我们对陆地生态系统建立关键时期的理解。还有适应性辐射的潜在机制。