Tackling taxonomic and taphonomic biases in the Triassic fossil fish record

解决三叠纪鱼类化石记录中的分类学和埋藏学偏差

• 批准号: 2436451
• 金额: --
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2436451
• 关键词: Tackling; taxonomic; taphonomic; biases; Triassic

Ray-finned fishes (actinopterygians) are the most diverse and successful group of vertebrates today, accounting for over half of living vertebrate species. In their nearly half-a-billion-year history they have survived countless mass extinctions, but, in contrast to many other groups, there is limited understanding of the effect of these devastating mass extinction events on their evolution. Despite thousands of exceptionally preserved two- and three-dimensional fossils from early Triassic deposits worldwide, there is a particularly poor understanding of how the Permo-Triassic Mass Extinction (252 million years ago) impacted ray-finned fishes. The reasons for this are two-fold: no robust hypothesis of the taxonomy and relationships of early Triassic ray-fins, and limited comprehension of the taphonomic processes that may have biased the Early Triassic fossil fish record. This project will combine CT scanning, phylogenetic analyses and taphonomic investigations to tackle these biases. Recent work has established a backbone of relationships amongst early actinopterygians, and the student will use a combination of traditional descriptive methods and CT scanning to place key early Triassic taxa into this phylogenetic framework and answer taxonomic questions. Much of our understanding of fish taphonomy and decay is based on teleost fishes, which display a very different morphology from early actinopterygians, in particular with regard to scale histology. Different types of squamation may have a profound impact on the preservation potential of different fish groups, potentially biasing the fossil record in this key period of earth's history and skewing our understanding of ray-finned fish recovery after the Permo-Triassic mass extinction. The student will investigate the effects of this through targeted interrogation of scale-bearing and scaleless taxa as well as taphonomic investigation of extant scale-bearing actinopterygians. This research will provide new insights into taphonomic processes acting on ray-finned fishes and the varying preservation potential of different fossil fish groups. It will also contribute to a revised hypothesis of actinopterygian relationships, answering fundamental questions concerning the impact of the Permo-Triassic mass extinction on the evolution of the largest living vertebrate clade.

射线鳍鱼类（放线菌）是最多样化和最成功的脊椎动物今天的群体，占一半以上的生活脊椎动物物种。在它们近5亿年的历史中，它们经历了无数次大规模灭绝，但与许多其他种群相比，人们对这些毁灭性的大规模灭绝事件对它们进化的影响了解有限。尽管在世界各地的三叠纪早期沉积物中发现了数千个保存完好的二维和三维化石，但人们对二叠纪-三叠纪大灭绝（2.52亿年前）如何影响鳍鳍鱼的了解特别少。原因有两个方面：没有强有力的假设的分类和关系的早三叠世鳍，和有限的理解的埋藏过程，可能有偏见的早三叠世化石鱼记录。该项目将结合联合收割机CT扫描，系统发育分析和埋藏调查，以解决这些偏见。最近的工作已经建立了早期放线菌之间的关系的骨干，学生将使用传统的描述方法和CT扫描相结合，把关键的早三叠纪类群到这个系统发育框架，并回答分类学问题。我们对鱼类埋藏学和腐烂的大部分理解都是基于硬骨鱼，硬骨鱼显示出与早期放线菌非常不同的形态，特别是在鳞片组织学方面。不同类型的鳞化可能对不同鱼类群体的保护潜力产生深远的影响，可能会在地球历史的这一关键时期偏向化石记录，并扭曲我们对二叠纪-三叠纪大灭绝后鳍鱼恢复的理解。学生将通过有针对性地询问有鳞和无鳞的分类群以及对现存的有鳞放线菌的埋藏学调查来研究这种影响。这项研究将提供新的见解埋藏作用于鳍鱼和不同的化石鱼类群体的保护潜力。它也将有助于修改的假设actinopterygian的关系，回答有关二叠纪-三叠纪大规模灭绝的最大的活脊椎动物进化支的进化的影响的基本问题。