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

Flessa 9417054 本文将研究一种活化石-舌形腕足类Glottidiapalmeri的埋藏学和生态学。 在寒武纪至现代的近岸沉积中，舌形目腕足动物是一种常见的具有重要古生态意义的化石。 它们的出现通常被认为是浅水、盐度变化的环境。 大量的舌形喉盘虫栖息在科罗拉多河三角洲的潮间带。 这些人口提供了一个难得的机会，研究控制这个物种的环境因素，生长的意义-带在壳，和死后的过程，影响保存和古环境解释的lingulid化石。 将从沿着两个海岸垂直断面采集样本：一个来自泥滩，另一个来自沙滩。 这些数据将被用来估计生活人口和他们的贝壳仍然是，和基板上的形态和埋藏的影响之间的对应关系。 埋藏分析将揭示埋藏特征可作为古环境指标的程度。 实地和实验室实验将评估埋葬和运输过程中死后变化的模式和速度。 将通过监测个体的生长情况以及通过将带型与气象和潮汐记录相联系来评价贝壳中扰动环的环境意义。 记录在叶舌科动物生长带中的季节性或捕食模式在叶舌科动物化石的研究中可以证明是有用的。 这项研究将是第一次全面研究的埋藏学的一个代表，这一共同的和地质学上有用的组。 我们的研究结果将影响现有的解释lingulid-轴承岩石，并将大大提高这一长期的顺序化石的古环境效用。

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.