CAREER:Ecological Diversification of Marine Mammals (Orders Cetacea and Sirenia) through Cenozoic Climate Change: Evidence from Geochemical Analysis of Fossil Material

通过新生代气候变化海洋哺乳动物（鲸目和海牛目）的生态多样性：来自化石材料地球化学分析的证据。Clementz，怀俄明州大学地质地球物理系 鲸目动物（例如，鲸鱼、海豚、鼠海豚）和海牛（例如，海牛：海牛、儒艮）是近岸和近海食物网的主要消费者，在调节这些群落的结构和组成方面发挥着重要作用。它们对水生生态系统的最早影响发生在50 Ma，当时第一头鲸鱼和海牛出现在化石记录中。地球化学和形态学证据都表明，这些群体已经对水中的生命有了很强的亲和力。在这一事件发生时或之后不久，在印度和巴基斯坦发现的每一目的新成员导致了大量化石材料的积累，记录了鲸鱼和海牛从陆地生态系统向海洋生态系统过渡的大多数关键步骤。收集到的大量材料使我们能够以更严格的定量方式研究这些群体的演变。这反过来又可以为这些群体的生态变化和形态进化之间的关系提供新的见解。 该项目的主要目标是在环境条件和新生代气候变化的背景下比较这两组海洋哺乳动物（鲸目和Sirenia）的进化生态学。随着鲸鱼和海牛在始新世早期的出现，这两个群体的进化和多样化发生在重大气候变化的主要事件中，因为地球从早第三纪的温室条件进入新第三纪和今天的冰库条件。为了有效地评估这种气候变化可能对每一种生物的进化产生的影响，我计划检查鲸鱼和海牛的标本，作为海洋食物网的组成部分。这就要求我不仅要了解个体或物种的饮食或营养位置，还要了解整个同时代海洋群落的饮食或营养位置。代表保存完好的海洋脊椎动物化石积累的关键地点（即，?骨床？）已从美国（加州、俄勒冈州、南卡罗来纳州）、埃及和新西兰的始新世、渐新世和中新世沉积物中鉴定出，并纳入本研究。我将主要依靠化石牙釉质的地球化学分析作为生态信息的代表。这种方法涉及钙，碳，氧和锶的稳定同位素的分析，以确定营养位置，饮食和盐度的耐受性，分别在这个项目下检查的每个人。因此，我的研究部分将集中在重建这些时间段的海洋食物网，以及确定鲸鱼和海牛在其中的作用。与此同时，我的教学内容也将强调一个综合的，大局观的方法来教育K-12和大学生的进化，生态和气候变化的概念。这将通过在现场和实验室和课堂活动，包括戏剧教育的研究相结合的努力，为学生提供心理刺激和评估的多种方法。这些努力将通过将这些教学活动和课程纳入当前的UWyo古研究计划来实现，这将通过博士后研究员，研究生，本科生和高中实习生的援助来实现。研究和教学工作相结合的目的是为学生提供一个机会，以获得对科学思维的更大的赞赏，以及更好地了解塑造他们周围的自然世界的过程。

CAREER:Ecological Diversification of Marine Mammals (Orders Cetacea and Sirenia) through Cenozoic Climate Change: Evidence from Geochemical Analysis of Fossil MaterialMark T. Clementz, Department of Geology & Geophysics, University of Wyoming Cetaceans (e.g., whales, dolphins, porpoises) and sirenians (e.g., sea cows: manatees, dugongs) are major consumers in nearshore and offshore foodwebs and play a strong part in regulating the structure and composition of these communities today. Their earliest influence on aquatic ecosystems occurred at 50 Ma, when the first whales and sea cows appeared in the fossil record. Both geochemical and morphological evidence suggest that these groups already had a strong affinity for life in the water. New discoveries of members of each order in India and Pakistan at or shortly after this event have led to a significant accumulation of fossil material documenting most of the critical steps within the transition from terrestrial to marine ecosystems by whales and sea cows. This wealth of collected material makes it now possible to examine the evolution of these groups in a more rigorous, quantitative manner. This, in turn, can provide new insights into the relationship between ecological change and morphological evolution for these groups. The primary goal of this project is to compare the evolutionary ecology of these two groups of marine mammals (Orders Cetacea and Sirenia) in the context of environmental conditions and Cenozoic climate change. With the appearance of whales and sea cows in the Early Eocene, the evolution and diversification of both groups occurred across major episodes of significant climate change as the Earth moved from the greenhouse conditions of the early Paleogene and into the icehouse conditions of the Neogene and today. In order to effectively evaluate the impact that this climate change may have had on the evolution of each, I plan to examine specimens of whales and sea cows as components of marine food webs. This requires that I not just understand the diet or trophic position of individuals or species, but of entire, coeval marine communities. Key localities representing well preserved marine vertebrate fossil accumulations (i.e., ?bone beds?) have been identified from Eocene, Oligocene and Miocene deposits in the USA (California, Oregon, South Carolina), Egypt and New Zealand for inclusion in this study. I will primarily rely on geochemical analysis of fossil tooth enamel as a proxy for ecological information. This approach involves the analysis of the stable isotopes of calcium, carbon, oxygen, and strontium to define the trophic position, diet, and salinity tolerances, respectively, of each individual examined under this project. Thus, my research component will focus on reconstructing marine food webs from these time periods as well as defining the role of whales and sea cows within them. At the same time, my teaching component will also emphasize an integrative, big-picture approach to educate K-12 and college students on the concepts of evolution, ecology and climate change. This will be done through a combined effort of research in the field and lab and classroom activities, including theater education, to provide students with multiple methods of mental stimulation and assessment. These efforts will be achieved by incorporating these teaching activities and lessons into the current UWyo paleo research program, which will be possible through the assistance of post-doctoral fellows, graduate students, undergraduates, and high school interns funded through this proposal and other sources available at UWyo. The combined research and teaching efforts are intended to provide an opportunity for students to gain a greater appreciation for scientific thinking as well as a better understanding of the processes shaping the natural world around them.