Morphological and phylogenetic changes of the hyobranchial apparatus from fishes to basal tetrapods.

从鱼类到基础四足动物的下鳃器的形态学和系统发育变化。

• 批准号: 200637233
• 负责人: Dr. Florian Witzmann
• 金额: --
• 依托单位: Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung (MfN)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/200637233?language=en
• 关键词: Morphological; phylogenetic; changes; hyobranchial; apparatus

The transformation of the hyobranchium (visceral skeleton) that requires fishes to suction feeding in water, to an apparatus that enables tongue-based terrestrial feeding, is a key aspect of the evolution of tetrapods, but is still poorly understood. The goal of this project is to recover the developmental changes of the hyobranchium during the fish-to-tetrapod transition in the Middle and Late Devonian. Several questions must be addressed including, (1) which structures of the hyobranchium of nontetrapods were conserved in basal tetrapods, (2) which were modified, and (3) how was the hyobranchium used for feeding and breathing in the different lineages of these animals? The project will focus on the morphological and phylogenetic investigation of the hyobranchial remains of Palaeozoic and Mesozoic basal tetrapods and their fish-like relatives. Two hypotheses will be tested: First, basal tetrapods retained a "fish-like" hyobranchium and fed on land by jaw prehension. Ontogenetic remodelling of the hyobranchium with the elaboration of a movable tongue skeleton evolved later in evolution, independently in the lineage leading to lissamphibians and to amniotes. Second, ontogenetic remodelling for a tongue-supporting hyobranchium evolved early in tetrapod history, and the retention of a "fish-like" hyobranchium is a paedomorphic trait. The better knowledge of phylogenetic changes of the hyobranchium would greatly improve our understanding of the fish-totetrapod transition and the origin of terrestriality in vertebrates.

需要鱼类在水中吸食的下鳃纲（内脏骨骼）转变为能够以舌头为基础的陆生进食的装置，是四足动物进化的一个关键方面，但人们仍然知之甚少。该项目的目标是恢复中、晚泥盆世鱼类向四足动物过渡过程中下鳃类的发育变化。必须解决的几个问题包括：（1）非四足动物的哪些下鳃结构在基础四足动物中是保守的，（2）哪些结构被修改了，以及（3）在这些动物的不同谱系中，下鳃是如何用于进食和呼吸的？该项目将重点对古生代和中生代基底四足动物及其类鱼近亲的下鳃遗迹进行形态学和系统发育研究。将测试两个假设：首先，基础四足动物保留了“鱼状”的下鳃纲，并在陆地上通过下巴抓捕进食。下鳃纲的个体发育重塑以及可移动的舌头骨骼的形成是在进化的后期进化的，独立地存在于导致游虫和羊膜动物的谱系中。其次，支持舌头的下鳃纲的个体发育重塑在四足动物历史的早期就已经进化，而“鱼状”下鳃纲的保留是一种幼态性状。更好地了解下鳃类的系统发育变化将极大地提高我们对鱼类-四足动物转变和脊椎动物陆生起源的理解。