Paleopathology in Late Triassic phytosaurs as a window to early archosauriform paleoecology, behavior and bone healing

三叠纪晚期植龙的古病理学是了解早期主龙古生态、行为和骨愈合的窗口

• 批准号: 459302527
• 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
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/459302527?language=en
• 关键词: Paleopathology; Late; Triassic; phytosaurs; window

Paleopathology, i.e. the study of ancient disease and injury, plays a significant role in understanding the physiology and paleoecology of long-extinct animals. Phytosaurs, a species-rich group of carnivorous archosauriforms, are well-suited for a large-scale paleopathological analysis because thousands of specimens are stored in museums in Europe and the US and – although not closely related – they can be compared with crocodylians which are often regarded as their extant ecological analogs. In spite of the large number of undescribed pathological specimens, no review of the spectrum and underlying causes of pathologies in phytosaurs exists up to date. The project has the goal to inform us about the lifestyle and behavior of phytosaurs based on a broad-based study of the types and frequencies of their skeletal pathologies. This applies especially to injuries which are indicative of an active lifestyle and are derived from trophic interactions (e.g. injuries caused by large and struggling prey), intraspecific aggression, or repetitive stress on bones and tendons. It will be assessed how type and frequency of pathologies in phytosaurs vary between different taxonomic groups, presumed trophic positions, and in the context of individual age. The nearly worldwide distribution of phytosaurs in Late Triassic continental ecosystems provides the rare opportunity to study their pathologies against the background of paleoenvironmental changes through time and between different geographical areas. The investigations will apply classic morphology, medical and micro-CT as well as histological thin sectioning. Synchrotron scanning of repair bone that was formed after injury will be carried out to assess if the kind of bone healing indicates a generally slower or faster growth rate of the skeleton in phytosaurs compared to other basal archosauriforms and in crocodylians. Furthermore, 3-D bone models derived from synchrotron scanning will be used as the basis for Finite Element Analyses (FEA) to gain an integrative picture of the mechanical consequences of the secondary bone remodeling after injuries. The comparison of phytosaur pathologies with those of extant crocodylians whose ecology and lifestyle are well known will test the hypothesis that comparable pathologies can be expected in phytosaurs and crocodylians due to an analogous lifestyle and similar morphology. The results will not only be important as independent tests of previous views on the paleobiology of phytosaurs. They will also provide a deeper insight in early archosauriform evolution and will lead to a better understanding of trophic interactions of tetrapods in Late Triassic continental ecosystems. Finally, the use of innovative methods in 3D-histology and biomechanics will allow to identify general relations between bone healing, growth rate, and the resulting consequences on the bone resistance.

古病理学，即对古代疾病和损伤的研究，在理解长期灭绝动物的生理和古生态学方面起着重要作用。植龙类是一个物种丰富的食肉类主龙形目，非常适合进行大规模的古病理学分析，因为成千上万的标本保存在欧洲和美国的博物馆里，尽管没有密切的关系，但它们可以与鳄鱼类进行比较，鳄鱼类通常被认为是它们现存的生态类似物。尽管有大量未描述的病理标本，但迄今为止，还没有对植龙类病理学的光谱和根本原因进行综述。该项目的目标是根据对植龙骨骼病理类型和频率的广泛研究，向我们介绍植龙的生活方式和行为。这尤其适用于表明积极生活方式的损伤，这些损伤来自营养相互作用（例如由大型和挣扎的猎物造成的损伤），种内攻击或骨骼和肌腱的重复应力。它将评估如何在植龙类的病理类型和频率不同的分类群体之间，假定的营养位置，并在个人年龄的背景下。植龙类在晚三叠世大陆生态系统中的几乎全世界的分布提供了难得的机会，以研究其病理学的背景下，通过时间和不同的地理区域之间的古环境变化。调查将采用经典的形态学，医学和显微CT以及组织学薄切片。将对受伤后形成的修复骨进行同步加速器扫描，以评估骨愈合的类型是否表明植龙类骨骼的生长速度通常比其他基底初龙形类和鳄鱼类更慢或更快。此外，来自同步加速器扫描的3-D骨模型将被用作有限元分析（FEA）的基础，以获得损伤后继发性骨重建的机械后果的综合图像。比较植龙的病理与现存的鳄鱼的生态和生活方式是众所周知的将测试的假设，可比的病理可以预期在植龙和鳄鱼由于类似的生活方式和相似的形态。这些结果不仅是对先前关于植龙古生物学观点的独立检验，而且也是重要的。它们还将提供更深入的了解早期初龙形的进化，并将导致更好地了解晚三叠世大陆生态系统中四足动物的营养相互作用。最后，在3D组织学和生物力学的创新方法的使用将允许确定骨愈合，生长速度和骨阻力的结果之间的一般关系。