Complexity of septal surfaces and suture lines in ammonoids - implications for the hydrostatic apparatus and palaeoecology using modern CT-techniques

菊石中间隔表面和缝合线的复杂性——使用现代 CT 技术对静水力装置和古生态学的影响

基本信息

批准号：
219700068
负责人：
Dr. René Hoffmann
金额：
--
依托单位：
Institut für Geologie, Mineralogie und Geophysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2012
资助国家：
德国
起止时间：
2011-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/219700068?language=en
关键词：
Complexity septal surfaces suture lines

项目摘要

In the course of the 350 million years (Lower Devonian-Upper Cretaceous) of ammonoid evolution the iterative trend of development starting with simple to complexly, folded septa of the phragmocon is well documented. In the literature different approaches on the role of marginal folded septa (= suture) are discussed. These can be divided mainly into physiological and mechanical explanations. By the calculations of the ratio of chamber volume against the inner chamber surface the functional model as hydrostatic apparatus is compared against all other known functional interpretations. On the basis of complete ammonites in hollow preservation (no sediment, calcite or pyrite in the shell) changes in that ratio are detectable. They allow statements about different lifestyles in different ontogenetic stages, and comparisons between different taxa. The creation of digital models also allows the specific examination of ontogenetic development from simple to complex sutures and thus the possibility to test for the taxonomic relevant mode of lobe insertion during sutural ontogeny. As working hypothesis we assume that the most complex structures found in late Cretaceous tetragonitids including the septal lobe and a sixlobate primary suture, in conjunction with presumed pelagic lifestyles on the shelf slope, most likely support the idea that they improve the efficiency of the hydrostatic apparatus as a key selection factor for the design of the septa. It is the main goal to prove whether or not this hypothesis is correct.

在氨水进化的3.5亿年（下泥盆纪 - 泥质白垩纪）的过程中，发育的迭代趋势从简单而复杂的折叠式杂货中得到了充分的记录。在文献中，讨论了关于边缘折叠隔sa的作用（=缝合）的不同方法。这些可以主要分为生理和机械解释。通过计算腔室体积与内室表面的比率，将功能模型作为静水设备与所有其他已知的功能解释进行了比较。根据空心保存中的完整氨（无沉积物，方解石或壳中的黄铁矿），该比率可检测到。它们允许在不同的个体发育阶段进行有关不同生活方式的陈述，并在不同的分类单元之间进行比较。数字模型的创建还允许对个体发育从简单到复杂的缝合线进行特定检查，因此有可能在经术性个体发育过程中测试叶插入的分类学相关模式。作为可行的假设，我们假设在白垩纪晚期四末期中发现的最复杂的结构在内，包括隔片叶和六叶酸盐原发性缝合线以及架子斜坡上假定的上层生活方式，很可能支持其提高水抑制剂作为kitelessections ofsection septa septa septa的钥匙选择的想法。这是证明该假设是否正确的主要目标。