Taphonomy and Paleoecological Significance of a Living Fossil: The Lingulid Brachiopod Glottidia palmeri

Fessa 9417054将研究一种活化石--舌状腕足类Glottidia Palmeri--的分类和生态学。在寒武纪至近代的近岸沉积中，腕足类化石十分常见，具有重要的古生态意义。它们的出现通常被认为是浅水、盐度变化的环境。在科罗拉多河三角洲的潮间滩上栖息着大量的舌状舌虫。这些种群提供了一个难得的机会来研究控制这个物种的环境因素，贝壳中生长-带状生长的意义，以及影响舌类化石的保存和古环境解释的死后过程。样本将沿着两个与海岸垂直的横断面采集：一个从泥滩，另一个从沙滩。这些数据将被用来估计活种群和它们的壳遗骸之间的对应关系，以及底物对形态和埋藏学的影响。农艺分析将揭示农艺特征在多大程度上可以作为古环境指标。现场和实验室实验将评估埋葬和运输过程中死后改变的模式和比率。将通过监测个体生长和通过将带状模式与气象和潮汐记录相关联来评估贝壳中干扰环的环境意义。在舌虫生长中记录的季节性或捕食模式--带状分布在舌虫化石的研究中被证明是有用的。这项研究将是第一次对这一常见的、在地质上有用的群体的代表性的割草学进行全面研究。我们的结果将影响现有的含舌泥质岩石的解释，并将极大地增强这一长期目化石的古环境效用。

Flessa 9417054 The taphonomy and ecology of a living fossil, the lingulid brachiopod Glottidia palmeri, will be examined. Lingulid brachiopods are common and paleoecologically significant fossils in nearshore deposits ranging from the Cambrian to the Recent. Their occurrence is often taken to indicate shallow--water, variable salinity environments. Large populations of the lingulid Glottidia inhabit the intertidal flats of the Colorado River delta. These populations present a rare opportunity to examine the environmental factors controlling this species, the significance of growth--banding in the shell, and the post-mortem processes that affect the preservation and paleoenvironmental interpretation of lingulid fossils. Samples will be collected from along two shore-perpendicular transects: one from mudflats, the other from sandflats. These data will be used to estimate the correspondence between live populations and their shelly remains, and the effects of substrate on morphology and taphonomy. Taphonomic analysis will reveal the extent to which taphonomic features can be used as paleoenvironmental indicators. Field and laboratory experiments will assess the patterns and rates of post-mortem alteration during burial and transport. The environmental significance of disturbance--rings in the shells will be evaluated both by monitoring individual growth and through correlating banding patterns with meteorological and tidal records. Patterns of seasonality or predation recorded in lingulid growth--banding can prove useful in studies of fossil lingulids. This study will be the first comprehensive study of the taphonomy of a representative of this common and geologically useful group. Our results will affect existing interpretations of lingulid--bearing rocks and will greatly enhance the paleoenvironmental utility of fossils of this long-ranging order.