Collaborative Research: Effects of Climatic/Environmental Change on Early Eocene Mammal Fauna of the Bighorn Basin, Wyoming

合作研究：气候/环境变化对怀俄明州大角盆地始新世早期哺乳动物群的影响。罗斯和艾米E。摘要为了了解气候/环境变化如何影响动物群的进化，PI将分析怀俄明州大角盆地中部始新世早期威尔伍德组哺乳动物群的变化。大角盆地中部的哺乳动物化石记录是这项分析的理想选择，因为它是密集的，广泛的研究，连续分布，并直接与精细尺度的气候/环境背景相关。该地区的威尔伍德组包括古新世/始新世热最大值（PETM），这是一个短暂而突然的全球变暖事件，与新生代哺乳动物历史上最引人注目的周转事件之一有关。在这一序列中确认的另外两个周转量较小的事件似乎与气候变化相对应，但证据是模棱两可的。该项目和其他正在进行的工作应有助于澄清这些事件。这项研究的目标是收集一个高分辨率，密集采样记录的动物群变化的古新世/始新世边界，并在第一个3 my的早始新世在中央大角盆地，特别是针对采样不足的间隔。 这将使从时间相等的间隔连续样本的比较，以评估物种的营业额，丰度，多样性，相对身体大小，并在始新世早期的营养结构的变化模式。由此产生的动物群随时间变化的全面记录将用于检验这些动物群变化与气候/环境变化之间的相互关系。 特别令人感兴趣的是温度变化的幅度和方向的变化以及降水量的波动对动物群的影响。

Collaborative Research: Effects of Climatic/Environmental Change on Early Eocene Mammal Fauna of the Bighorn Basin, WyomingKenneth D. Rose and Amy E. Chew, co-PIsABSTRACT In order to understand how climatic/environmental change influences faunal evolution, the PIs will analyze changes in the mammalian faunas of the early Eocene Willwood Formation in the central part of the Bighorn Basin, Wyoming. The record of fossil mammals from the central Bighorn Basin is ideal for this analysis as it is dense, extensively studied, continuously distributed and directly associated with a fine-scale climatic/environmental context. The Willwood Formation in this area includes at its base the Paleocene/Eocene thermal maximum (PETM), a brief and abrupt episode of global warming, which is associated with one of the most dramatic turnover events in the history of Cenozoic mammals. Two other lesser turnover events recognized in this sequence appear to correspond to climatic shifts, but the evidence is equivocal. This project and other ongoing work should help to clarify these events. The goal of the study is to assemble a high-resolution, densely sampled record of faunal change across the Paleocene/Eocene boundary and during the first 3my of the early Eocene in the central Bighorn Basin, especially targeting under-sampled intervals. This will enable a comparison of successive samples from time-equal intervals, in order to evaluate patterns of species turnover, abundance, diversity, relative body size, and change in trophic structure during the early Eocene. The resulting comprehensive record of faunal change over time will be used to test the correlation between these faunal changes and climatic/environmental changes. Of particular interest will be the effect on faunas of variation in the magnitude and direction of shifting temperature and of fluctuation in precipitation.