COLLABORATIVE RESEARCH: Evolutionary Success in Marine Invertebrates: Testing the Relationships between Eurytopy, Longevity, and Geographic Range in Carboniferous Crinoids

海洋无脊椎动物的进化成功：石炭纪海百合的eurtopy，寿命和地理范围之间的关系测试本研究将重点研究环境和生物地理因素在海百合（棘皮动物）的进化成功中的作用，海百合是古生代最多样化和最丰富的海洋无脊椎动物群体之一。下石炭世（354 ~ 314亿年前）岩石在其进化史上记录了海百合属多样性的高峰。进化的成功是通过化石记录中的分类寿命来衡量的。目前对进化成功原因的理解尚不完整，但现有证据表明，进化与环境宽度（eurytopy）和地理范围呈正相关。支持这种相关性的数据在古生代海洋无脊椎动物中是有限的。因此，对早石炭世海百合的分析将更严格地检验这种相关性，并拓宽我们对海洋无脊椎动物的多样性、寿命和地理范围之间关系的理解。该研究将比较北美和欧洲这两个拥有最佳化石记录的地区海麻类群（亚目）中属的平均地层（寿命）、环境（地形）和地理范围。这项研究将包括北美早石炭纪（早石炭纪）的Kinderhookian到早期Meramecian时代，以及西欧早石炭纪的Tournaisian到中期Visean时代。属的地层和地理范围将通过评估所有已知的物种来确定正确的属分配。同时，将把两大洲属的环境分布数据制成表格，以计算大陆内和洲际上每个属的群落指数值。这项调查的结果将直接影响到试图解释地球上生命历史的进化论。从这项研究中获得的广泛数据集将有助于阐明环境和地理在决定一般寿命和最终确定进化成功的群体寿命方面的作用。

COLLABORATIVE RESEARCH: Evolutionary Success in Marine Invertebrates: Testing the Relationships between Eurytopy, Longevity, and Geographic Range in Carboniferous CrinoidsThis study will focus on the role of environmental and biogeographic factors in the evolutionary success of crinoids (echinoderms), one the most diverse and abundant groups of marine invertebrates during the Paleozoic. Lower Carboniferous (354 to 314 m.y. ago) rocks record the peak of crinoid generic diversity during their evolutionary history. Evolutionary success is measured by taxonomic longevity in the fossil record. Current understanding of reasons for evolutionary success is incomplete, but available evidence indicates a positive correlation with environmental breadth (eurytopy) and geographic range. Data supporting this correlation are limited for Paleozoic marine invertebrates. Thus, analysis of Early Carboniferous crinoids, where preliminary work supports such a correlation, will more rigorously test the correlation and broaden our understanding of the relationships between eurytopy, longevity, and geographic range in marine invertebrates. The research will compare the average stratigraphic (longevity), environmental (eurytopy), and geographic ranges of genera within crinoid groups (suborders) between North America and Europe, the two regions with the best fossil record. The study will include the Kinderhookian to early Meramecian epochs of the Mississippian Period (Early Carboniferous) of North America and the equivalent Tournaisian to middle Visean epochs of the Early Carboniferous of western Europe. Stratigraphic and geographic ranges of genera will be determined by evaluating all known species for correct generic assignment. Simultaneously, data on environmental distribution will be tabulated for genera on both continents to calculate a eurytopy index value for each genus, both intracontinental and intercontinental. Results of this investigation will bear directly on evolutionary theory as it endeavors to explain the history of life on Earth. The extensive data set derived from this study will help elucidate the roles of environment and geography in determining generic longevity and, ultimately, group longevity in defining evolutionary success.