Palaeoecology and migration behaviour of the Palaeozoic to Mesozoic freshwater sharks Lissodus and Orthacanthus using stable isotopes

使用稳定同位素研究古生代至中生代淡水鲨鱼 Lissodus 和 Orthacanthus 的古生态学和迁徙行为

• 批准号: 58201536
• 负责人: Professor Dr. Jörg W. Schneider
• 金额: --
• 依托单位: Institut für Geowissenschaften (IfG)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/58201536?language=en
• 关键词: Palaeoecology; migration; behaviour; Palaeozoic; Mesozoic

Shark remains are abundant in Late Palaeozoic and Mesozoic continental deposits. The palaeoecology of these fishes is discussed either as permanent freshwater residents or as anadromous animals, which seasonally migrated into freshwater environments for spawning. The aim of this project is the investigation of the geochemical archive of teeth and spines of the fossil freshwater sharks Lissodus and Orthacanthus based on two case studies from the Permo-Carboniferous and the Late Triassic using stable isotopes. The oxygen isotopic composition of skeletal apatite reflects the ambient water chemistry at the time of tooth mineralisation being indicative for a fresh- or seawater environment. Furthermore, freshwater isotopic signals allow the evaluation of the relative altitude of shark-bearing lakes in order to specify the palaeotopography and drainage pattern of orogenic belts and their basins. In addition, the spatial and temporal distribution of freshwater sharks will be critically assessed by the occurrences of possibly related egg capsules. The new freshwater-shark-derived oxygen isotope data set will provide new insights about the isotopic composition of meteoric waters and the hydrology in Late Palaeozoic and Early Mesozoic times.

晚古生代和中生代大陆沉积物中鲨鱼遗骸丰富。这些鱼类的古生态学被讨论为永久淡水居民或季节性迁徙到淡水环境产卵的溯河产卵动物。该项目的目的是基于二叠纪-石炭纪和晚三叠世的两个案例研究，利用稳定同位素对淡水鲨鱼化石 Lissodus 和 Orthacanthus 的牙齿和脊柱的地球化学档案进行调查。骨骼磷灰石的氧同位素组成反映了牙齿矿化时的环境水化学，指示淡水或海水环境。此外，淡水同位素信号可以评估有鲨鱼的湖泊的相对高度，以便确定造山带及其盆地的古地形和排水模式。此外，淡水鲨鱼的空间和时间分布将通过可能相关的卵囊的出现情况进行严格评估。新的淡水鲨鱼氧同位素数据集将为大气水的同位素组成以及古生代晚期和中生代早期的水文学提供新的见解。