Paleoclimate and Paleoecology in High Latitude, Terrestrial Vertebrate Communities from the Early-Middle Eocene of Ellesmere Island, Nunavut, Arctic Canada

加拿大北极地区努勒维特埃尔斯米尔岛早中始新世高纬度陆生脊椎动物群落的古气候和古生态

• 批准号: 0454906
• 负责人: Jaelyn Eberle
• 金额: --
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-03-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0454906&HistoricalAwards=false
• 关键词: Paleoclimate; Paleoecology; Latitude; Terrestrial; Vertebrate

The Principal Investigators will test hypotheses concerning the Eocene global warm period and its effects on high-latitude terrestrial ecosystems by reconstructing paleoclimate and -ecology from d18O(PO4), d18O(CO3), and d13C values of biogenic phosphate in vertebrate tooth enamel from Early-Middle Eocene localities on Ellesmere Island, Canada (~79degrees N). Specifically, they will test the hypothesis that Eocene vertebrates inhabiting the High Arctic preferred temperatures and habitats similar to their living analogs and are therefore accurate paleoclimate and paleoecologic proxies. By comparison to published sea surface temperatures (SSTs), the Principal Investigators will test the hypothesis that quantitative climate changes in northern high-latitude terrestrial environments correlate to those determined for high-latitude open marine environments. The project will provide quantification of latitudinal gradients by determining d18O values of multiple vertebrate taxa (e.g., alligators, brontotheres, and tapirs) that co-occur in mid- and high-latitude North America. Quantitative climate estimates for Early - Middle Eocene localities on Ellesmere Island should also provide data critical to understanding the onset of the Cenozoic cooling trend, purported to have begun with during early Middle Eocene time. Comparison of the Eocene mammals, particularly the large herbivores, from Ellesmere Island with living relatives and analogues, combined with d13C analysis of the biogenic phosphate in their teeth, should provide insight into their habitat preferences (i.e., open habitat vs. closed canopy). Additionally, comparison of d13C values from the same genera coexisting at both mid- and high-latitudes (e.g., Coryphodon and the brontotheres Eotitanops and Palaeosyops) may illuminate important paleoecological differences that would otherwise not be evident in their morphology. Extensive paleontological field work in Eocene strata of the Eureka Sound Group on Ellesmere Island by the Principal Investigators provides paleoclimatic and paleoenvironmental estimates that are inferred from the fossil plants and animals, in addition to numerous specimens on which to conduct isotope analysesBroader Impacts: This project will result in the first comprehensive, quantitative paleoclimate data set from northern high-latitude terrestrial environments for the most significant global warming event in the last 65 million years (the Early Eocene), which is critical to understanding the impacts of future global warming on Earth's biota. The research will provide important high-latitude terrestrial data points for paleoclimate modelers concerned with Eocene climatic variability and latitudinal temperature gradients. This study will be the first to infer paleoecology of a high Arctic terrestrial vertebrate community on the basis of coupled carbon and oxygen isotope analyses (in conjunction with comparisons to mid-latitude taxa and modern analogs). The project will engage students, the general public (including the Inuit community), and scientists in a multidisciplinary, collaborative research alliance, and foster international and intercultural discourse. Results of the research will be broadly disseminated to scientific and lay audiences.

首席研究人员将通过重建D18O（PO4），D18O（CO3）（CO3）和D13C的生物源性磷酸盐植物的生物磷酸盐（po4）（CO3）和D13C值来测试有关始新世全球温暖时期及其对高寿命陆地生态系统的影响的假设。 n）。 具体而言，他们将检验以下假设：始新世脊椎动物居住在高北极优选的温度和类似于其生活类似物的栖息地，因此是准确的古气候和古生物代理。 与已发表的海面温度（SST）相比，主要研究人员将检验以下假设：北部高纬度陆地环境的定量气候变化与高纬度开放式海洋环境确定的气候相关。 该项目将通过确定在北美中部和高纬度的多个脊椎动物分类单元（例如，鳄鱼，勃朗特人和tap）的D18O值（例如，鳄鱼，勃朗特人和tap）来量化纬度梯度。 埃尔斯米尔岛（Ellesmere Island）上始新世早期始新世区域的定量气候估计还应提供至关重要的数据，以了解在始新世的早期始新世时期开始始于新生代冷却趋势的发作。比较来自埃尔斯米尔岛（Ellesmere Island）的始新世哺乳动物，尤其是大型草食动物，以及与生物的亲属和类似物的比较，再加上对生物磷酸盐在牙齿中的D13C分析，应提供对其栖息地偏好的见解（即开放式栖息地与封闭的封闭式盖层）。 此外，比较来自中属和高贴属的同一属的D13C值（例如，Coryphodon和Brontotheres eotitanops和palaeosyops）可能会阐明重要的古生物学差异，否则这些差异在其形态学中否则不明显。首席研究人员在埃勒斯米尔岛的尤里卡岛始新世层进行广泛的古生物学现场工作，提供了从化石植物和动物中推断出的古气候和古环境估计值，除了许多标本外，还可以在众多标本中对同位素进行高度构建的范围，以备受地位的范围。在过去的6500万年中（始新世早期），全球重大变暖事件对于理解未来全球变暖对地球生物群的影响至关重要。 该研究将为与始新世气候变异性和纬度温度梯度有关的古气候建模者提供重要的高纬度陆生数据点。 这项研究将是第一个根据耦合的碳和氧同位素分析来推断高北极脊椎动物群落的古生物学（与中纬度分类单群和现代类似物的比较结合使用）。 该项目将与学生，公众（包括因纽特人社区）和科学家参与多学科，合作研究联盟以及培养国际和跨文化话语。 该研究的结果将广泛地传播到科学和外行观众中。