Paleoecological Setting of Eocene Echinoderms at Seymour Island, Antarctic Peninsula

9315927布莱克9413295阿伦森该奖项支持对南极半岛西摩岛始新世拉梅塞塔组棘皮动物化石的研究。这一地层代表了浅海条件，它包含了世界上最多样化的棘皮动物化石组合之一。西摩岛棘皮动物群的特征更像古生代棘皮动物群落，而不是绝大多数其他新生代浅水群落。目前的想法表明，形态上新颖的海洋生物主要起源于近岸、异质环境，然后扩展到近海、更同质的环境。古生代以后，这种近岸-近海格局被认为在很大程度上是由捕食压力驱动的。La Meseta棘皮动物的发现表明，始于中生代的群落重组可能要到早新生代才能完成。这项研究将扩展对西摩岛棘皮动物的分类工作，并将评估捕食在星形动物和海鞘动物种群中的意义。这一信息将使我们能够与其他棘皮动物化石和现代棘皮动物进行比较，并提供棘皮动物古生态的罕见视角。具体地说，这项研究将对始新世浅海近极环境中的捕食压力是棘皮动物群落的重要强迫机制这一假说进行重要的检验。***

9315927 Blake 9413295 Aronson This award supports a study of echinoderm fossils from the Eocene La Meseta Formation of Seymour Island in the Antarctic Peninsula. This formation represents shallow marine conditions and it contains one of the most diverse fossil echinoderm assemblages in the world. The Seymour Island echinoderm fauna has characteristics more like Paleozoic echinoderm communities than like the great majority of other Cenozoic shallow water communities. Current thinking suggests that morphologically novel marine organisms originated primarily in near shore, heterogeneous environments, and then expanded to offshore, more homogeneous environments. After the Paleozoic, this pattern of near shore-offshore pattern is thought to have been driven largely by predation pressure. The La Meseta echinoderm occurrences suggest that the community reorganization that began in the Mesozoic may not have been completed until the early Cenozoic. This research will extend the taxonomic work on the echinoderms from Seymour Island and it will evaluate the significance of predation in stelleroid and crinoid populations. This information will allow a comparison with other echinoderm occurrences, both fossil and modern, and will provide a rare view of echinoderm paleoecology. Specifically, this research will allow an important test of the hypothesis that predation pressure in shallow-marine near-polar environments during the Eocene was an important forcing mechanism for echinoderm communities. ***