Palaeobiology, morphology and diversity of macrofaunas: A case study on Early Cretaceous ammonites

大型动物的古生物学、形态和多样性：以早白垩世菊石为例

基本信息

批准号：
175607855
负责人：
Professor Dr. Jens Lehmann
金额：
--
依托单位：
Geowissenschaftliche Sammlung
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/175607855?language=en
关键词：
Palaeobiology morphology diversity macrofaunas case

项目摘要

The background for control mechanism regarding fluctuations in the abundance, diversity and morphological changes of fossil invertebrates is a complex but seminal field. Particularly the nutrient and sediment supply may be a major affluent on macrofossil fluctuations and essential for reconstructing their environmental background, but is not yet in the focus of current research. We plan to use associations of benthic and planktic foraminifers and calcareous nanoplankton to reconstruct oxygen and nutrient levels for Early Cretaceous oceans and to apply these data to the interpretation of ammonite ecology as a case for other macrofossil groups. This is considered an urgent matter of research, since ammonites are among the dominant and most important invertebrates of their times and their position in the food web may be a key for understanding marine ecosystems on the Mesozoic shelf. Only a few pioneer studies support this hypothesis yet, underlining the urgency of the matter. We propose to cover the bio- and lithofacies interpretation by sedimentological data and the independent time-control and correlation of sections by stable isotope supported by gamma ray data. Since nutrient supply is steered by climate conditions, we chose prime profiles across climatic belts in the Tethys, the central Atlantic as well as in northern Europe. We choose the Lower Aptian as a key substage, since this time interval contains the most prominent Early Cretaceous Oceanic Anoxic Event with a very wide distribution of low oxygen conditions, excellent carbon isotope records and the chance to study long and short term changes prior to, during and subsequent to the event.

无脊椎动物化石的丰度、多样性和形态变化的控制机制的背景是一个复杂但具有影响力的领域。特别是营养物和沉积物供应可能是大型化石波动的主要来源，对于重建其环境背景至关重要，但尚未成为当前研究的重点。我们计划利用底栖和浮游有孔虫以及钙质纳米浮游生物的组合来重建早白垩世海洋的氧气和营养水平，并将这些数据应用于解释菊石生态学，作为其他大型化石群的案例。这被认为是一个紧迫的研究问题，因为菊石是当时占主导地位和最重要的无脊椎动物之一，它们在食物网中的地位可能是了解中生代陆架海洋生态系统的关键。目前只有少数先驱研究支持这一假设，凸显了问题的紧迫性。我们建议涵盖沉积学数据的生物和岩相解释以及伽马射线数据支持的稳定同位素的独立时间控制和剖面相关性。由于养分供应受气候条件影响，我们选择了特提斯、大西洋中部以及北欧气候带的主要剖面。我们选择下阿普第阶作为一个关键的子阶段，因为这个时间间隔包含最突出的早白垩世海洋缺氧事件，低氧条件分布非常广泛，碳同位素记录良好，并且有机会研究在此之前的长期和短期变化，活动期间和活动之后。