Environmental and Taxonomic Control of Growth, Morphology, Taphonomy, and Sediment Production in Living Stalked Crinoids (Echinodermata)

9628215梅辛潜行海鲷是生物组合的主要组成部分，对小巴哈马海岸西侧的现代骨骼沉积物有重要贡献。为了更好地了解现代海百合沉积物的生产过程、速率和死后修饰，本文从三个方面对海百合生物学和地学进行了研究：1)在不同深度和不同环境条件下，不同物种间和物种内的生长速率如何变化？生长速度是通过经过验证的标记和恢复方法直接测量的，这些方法允许在原位维护标本。2)水深和环境条件在多大程度上控制海百合形态？目前应用于海百合物种诊断和系统发育假说的许多特征在个体发育、生态表型、地理和/或深度对称性上各不相同。对海百合种类的认识和认识对生物地层分析、古生态重建和假说检验具有重要意义。应用先前成功的标记和恢复实验将允许标本移植到不同的栖息地和深度。3)类群之间和类群内部的形态和生态变化如何影响茎断断模式、骨骼沉积物生成速率和构成沉积物的骨骼颗粒的性质等分形过程，以及如何将这些信息应用于化石组合的重建？结合活体和实验分解的海百合茎的解剖和岩石学薄片和扫描电子显微镜，以及从沉积物中提取的骨骼颗粒，用于检查韧带解剖，韧带腐烂的模式以及与茎降解增加相关的胶结物的发展。研究生物的化石记录可以追溯到三叠纪。因此，这些现代组合为更好地理解古生态过程和解释古代海砂沉积提供了很好的模拟。拟研究的海百合生态学和埋藏学的各个方面是完全相互关联的，代表了在先前建立的研究地点由美国国家科学基金会资助的成功研究计划的逻辑延伸。

9628215 Messing Stalked crinoids represent a major component of living assemblages and contribute substantially to modern skeletal sediments along the western flank of the Little Bahama Bank. Three aspects of stalked crinoid biology and taphonomy are examined in order to better understand the processes and rates of production, and post-mortem modifications of modern crinoidal sediments, as follows: 1) How do growth rates among different species and within species vary at different depths and under different environmental conditions? Growth rates are measured directly via proven methods of tagging and recovery that permit in situ maintenance of specimens. 2) To what extent do depth and environmental conditions control crinoid morphology? Many features currently applied to crinoid species diagnoses and phylogenetic hypotheses vary ontogenetically, ecophenotypically, geographically and/or bathymetrically. Clear understanding and recognition of crinoid species are critical to biostratigraphic analyses and paleoecological reconstruction and hypothesis-testing. Application of previously successful tag-and-recovery experiments will permit specimens to be transplanted to different habitats and depths. 3) How do morphological and ecological variations among and within taxa affect taphonomic processes such as patterns of stalk disarticulation, skeletal sediment production rates, and the nature of skeletal grains contributed to sediments, and how can this information be applied to reconstruction of fossil assemblages? A combination of anatomic and petrographic thin sections and scanning electron microscopy of living and experimentally decomposed crinoid stalks, and skeletal grains retrieved from sediments are used to examine ligament anatomy, the pattern of ligament decay and the development of cements relative to increasing stalk degradation. The study organisms have a fossil record dating to the Triassic. As such, these modern assemblages represent an excellent analogue for better understan ding paleoecological processes and interpreting ancient crinoidal deposits. The aspects of crinoid ecology and taphonomy proposed for study are thoroughly interconnected and represent a logical extension of the successful research program carried out under prior NSF funding at previously established study sites.