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Inferring the Swimming Mode of Jurassic Plesiosaurs Using Muscle Reconstructions, Bone Histology, and Advanced Finite Element Methods

利用肌肉重建、骨组织学和先进有限元方法推断侏罗纪蛇颈龙的游泳模式

基本信息

批准号：
270835314
负责人：
Professor Dr. Martin Sander
金额：
--
依托单位：
Abteilung Paläontologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/270835314?language=en
关键词：
Inferring Swimming Mode Jurassic Plesiosaurs

项目摘要

After the end-Permian mass extinction, the marine realm quickly recovered, including an adaptive radiation of marine reptiles. One of the most important and long-lasting radiation is the one of the Sauropterygia, of which the Plesiosauria are the most aquatic representatives. The radiation of Plesiosauria occurred in the Jurassic and Cretaceous and lead to a great diversity of taxa but to a low morphological disparity, especially in terms of their extremities. The flippers were transformed to four very similarly-shaped hydrofoils. The locomotor system of plesiosaurs remained practically unchanged for about 135 Ma, implying an optimized energy efficiency for their habitat. Plesiosaurs evolved a unique way of underwater flight in which they employed two pairs of flippers of very similar appearance. Yet, how plesiosaurian underwater flight took place remains unknown due to a lack of fossil and modern analogues. Hence plesiosaur swimming is one of the most challenging phenomena in vertebrate locomotion. We would like to contribute to solving this evolutionary problem by a transdisciplinary set of methods from ingeneering science, paleontology, and biology. First, Caretta caretta, a recent marine turtle will be dissected, measured, and documented for comparison and to gain data that will be used for different finite element methods. The methods include finite element structural analysis (FESA), finite element structural synthesis (FESS), and computational fluid dynamics (CFD). Then plesiosaur flipper muscles will be reconstructed using phylogenetic inference (Extant Phylogenetic Bracket), osteologic correlates, and bone histology. Thorough muscle reconstructions are needed to calculate possible muscle forces with FESA. The results will form the basis for FESS computations to produce finite element syntheses of humeri und femora of Caretta caretta and a plesiosaur. If results of the virtual syntheses match with the fossil finds of plesiosaurs and the preserved specimens of Caretta caretta, muscle reconstructions will be verified. With CFD, possible swimming speeds and the fluid dynamic properties of the plesiosaur flippers will be determined.

在二叠纪末大灭绝之后，海洋领域迅速恢复，包括海洋爬行动物的适应性辐射。最重要和最持久的辐射之一是龙类，其中蛇颈龙是最水生的代表。蛇颈龙类的辐射发生在侏罗纪和白垩纪，导致了分类群的巨大多样性，但形态差异较小，特别是在四肢方面。鳍状肢被改造成四个形状非常相似的水翼。蛇颈龙的运动系统在大约135 Ma的时间里几乎没有变化，这意味着它们的栖息地具有最佳的能量效率。蛇颈龙进化出一种独特的水下飞行方式，它们使用两对外观非常相似的鳍状肢。然而，蛇颈龙的水下飞行是如何发生的仍然未知，因为缺乏化石和现代类似物。因此蛇颈龙游泳是脊椎动物运动中最具挑战性的现象之一。我们希望通过工程科学、古生物学和生物学的跨学科方法来解决这个进化问题。首先，Caretta caretta，最近的海龟将被解剖，测量，并记录比较，并获得数据，将用于不同的有限元方法。这些方法包括有限元结构分析（FESA）、有限元结构综合（FESS）和计算流体动力学（CFD）。然后，蛇颈龙鳍状肌将重建系统发育推断（现存系统发育分析），骨学相关，骨组织学。需要彻底的肌肉重建来计算FESA可能的肌肉力量。结果将形成FESS计算的基础上产生的Caretta caretta和蛇颈龙的肱骨和股骨的有限元合成。如果虚拟合成的结果与蛇颈龙化石和保存的Caretta caretta标本相匹配，肌肉重建将得到验证。通过计算流体动力学，将确定蛇颈龙鳍状肢可能的游泳速度和流体动力学特性。