Ontogenetic variation of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis: Implications for the palaeobiology of early archosaurs

中三叠世拟鳄类 Batrachotomus kupferzellensis 的个体发生变异：对早期古龙古生物学的启示

• 批准号: 325969278
• 负责人: Dr. Christian Foth
• 金额: --
• 依托单位: Staatliches Museum für Naturkunde Stuttgart - Zentrum für Biodiversitätsforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/325969278?language=en
• 关键词: Ontogenetic; variation; Middle; Triassic; pseudosuchian

The clade of Archosauria consists of two main clades, the Ornithodira (including extant birds) and the Pseudosuchia (including extant crocodylians), and represents one of the most successful clades among tetrapods. Most of our knowledge of the palaeobiology of Mesozoic archosaurs (e.g. intraspecific variation, growth physiology and functional morphology) is based on ornithodirans (i.e. non-avian dinosaurs and pterosaurs), whereas respective knowledge is limited for early pseudosuchians, although the latter evolved a great taxonomic and ecological diversity, especially in the Triassic period. Due the availability of several specimens of different ontogenetic stages the pseudosuchian Batrachotomus kupferzellensis from the Middle Triassic outcrops of Baden Württemberg, which represents one of the terrestrial top predators during this time period, represents an appropriate object to study the palaeobiology of early pseudosuchians. Thus, the aim of the proposed project is to obtain better insights into this topic, using the Batrachotomus kupferzellensis as a model organism. Important questions to be answered during this project include the following: How long did Batrachotomus kupferzellensis take to grow to adult size and when did it reach sexual maturity? How far was its growth subject to seasonality? What does this tell us about growth rates in this taxon? Did the animal growth uniformly within different body regions? What are main ontogenetic changes in the osteology of Batrachotomus kupferzellensis? Are there changes in dentition (e.g. serration, morphology of teeth)? Do these data reveal ontogenetic differences in ecology, e.g. in terms of locomotion and feeding behaviour? If comparing the data with that of extant crocodylians, other basal pseudosuchians and basal dinosaurs, does the ontogenetic data of Batrachotomus kupferzellensis provide any evidence for heterochronic events in early archosaur evolution? What are the plesiomorphic ontogenetic and growth patterns of the hypothetical ancestor of Archosauria? The central methods to answer these questions will be the analysis of bone histology, morphometrics, detailed studies of the osteology as well as three-dimensional reconstructions of internal cranial structures based on MicroCT data. In sum, the proposed project will help to learn more about the palaeobiology of Batrachotomus kupferzellensis and closely related species, which also helps to understand their role as top-predators in the terrestrial ecosystems of the Triassic. Due to a wider comparison with other Archosauriformes, the project will obtain deeper insights in the palaeobiology of Triassic pseudosuchians and basal archosaurs in general.

主龙类分支由两个主要分支组成：鸟龙类（包括现存鸟类）和拟鳄类（包括现存鳄鱼类），是四足动物中最成功的分支之一。我们对中生代祖龙古生物学的大部分了解（例如种内变异、生长生理学和功能形态）都是基于鸟龙类（即非鸟类恐龙和翼龙），而对早期拟鳄类的相关知识有限，尽管后者进化出了巨大的分类学和生态多样性，特别是在三叠纪时期。由于存在不同个体发育阶段的多个标本，来自巴登符腾堡州中三叠世露头的拟鳄类 Batrachotomus kupferzellensis 代表了这一时期的陆地顶级捕食者之一，是研究早期拟鳄类古生物学的合适对象。因此，该项目的目的是使用 Batrachotomus kupferzellensis 作为模式生物，更好地了解这一主题。该项目需要回答的重要问题包括：Batrachotomus kupferzellensis 需要多长时间才能长到成年体型以及何时达到性成熟？其增长在多大程度上受季节性影响？关于该分类单元的增长率，这告诉我们什么？动物身体不同部位的生长是否一致？ Batrachotomus kupferzellensis 骨学的主要个体发生变化是什么？牙列是否有变化（例如锯齿、牙齿形态）？这些数据是否揭示了生态学中的个体发生差异，例如在运动和进食行为方面？如果将这些数据与现存的鳄鱼类、其他基础拟鳄类和基础恐龙的数据进行比较，Batrachotomus kupferzellensis的个体发育数据是否为早期祖龙进化中的异时事件提供了任何证据？假想的主龙类祖先的拟态个体发生和生长模式是什么？回答这些问题的核心方法将是骨组织学、形态测量学分析、骨学详细研究以及基于 MicroCT 数据的颅内结构三维重建。总之，拟议的项目将有助于更多地了解 Batrachotomus kupferzellensis 和密切相关物种的古生物学，这也有助于了解它们作为三叠纪陆地生态系统中顶级捕食者的作用。由于与其他古龙形目进行更广泛的比较，该项目将获得对三叠纪拟鳄类和基础古龙的古生物学的更深入的了解。