COLLABORATIVE RESEARCH: Evaluating the Contribution of Late Cretaceous Biogeography to Earliest Cenozoic Biodiversity in North America

合作研究：评估晚白垩纪生物地理学对北美最早新生代生物多样性的贡献在这个项目中，研究人员将使用新墨西哥州圣胡安盆地Kirtland组Naashoibito成员中最近发现的多样化陆生微脊椎动物化石组合来测试以下假设：(1)北美晚白垩纪存在哺乳动物的区系省部性；(2)北美洲最早新生代的恢复动物群至少部分来源于北美洲晚白垩世的不同地区。在白垩纪末期大灭绝之后，陆地生态系统的恢复在北美西部内陆的研究中最为人所知。这种恢复的典型特征是在晚白垩纪之前的北美出现了谱系未知的哺乳动物。这可能是因为对最新白垩纪哺乳动物群的了解在地理上仅限于西部内陆的北部地区。通过收集这些新的南方动物群，更好地确定Naashoibito成员的年龄，并将这些新的动物群纳入现有系统发育和生物地理数据库的分析中，研究人员将进一步了解最近一次大灭绝之前的生物地理因素如何促进随后的陆地生态系统恢复。该项目的第二个目标是通过参与原创性研究来培养本科生，部分针对美国原住民学生。科特兰组沿纳瓦霍（丁）族边缘露头；这个项目提供了一个独特的机会，让Dine的学生了解他们家乡的地质历史和脊椎动物化石资源，以及实地和实验室研究方法。该项目的研究结果将被纳入该地区理科专业学生和职前K-12教师的本科地球科学课程。

Collaborative research: Evaluating the contribution of Late Cretaceous biogeography to earliest Cenozoic biodiversity in North AmericaAnne Weil, Thomas Williamson, Steven SemkenIn this project, the investigators will use a recently discovered, diverse, terrestrial microvertebrate fossil assemblage, found in the Naashoibito Member of the Kirtland Formation, in the San Juan Basin of New Mexico, to test the following hypotheses: (1) that there was mammalian faunal provinciality in the latest Cretaceous of North America, and; (2) that recovery faunas of earliest Cenozoic North America are derived at least in part from diverse provinces present in Late Cretaceous North America. Terrestrial ecosystem recovery following the end-Cretaceous mass extinction is best known from studies of the North American Western Interior. This recovery is typified by the appearance of mammals whose lineages are unknown from North America in the preceding Late Cretaceous period. That may be because knowledge of latest Cretaceous mammalian faunas has been geographically restricted to the northern region of the Western Interior. In collecting this new, southern fauna, better establishing the age of the Naashoibito Member, and incorporating this new fauna in analyses of existing phylogenetic and biogeographic data bases, the investigators will advance understanding of how biogeographic factors preceding the most recent mass extinction contributed to the subsequent recovery of terrestrial ecosystems.A secondary goal of this project is undergraduate education through involvement in original research, directed in part toward Native American students. The Kirtland Formation outcrops along the edge of the Navajo (Dine) Nation; this project offers an unique opportunity to educate Dine students in the geological history and vertebrate fossil resources of this part of their homeland, as well as in field and laboratory research methods. The findings of this project will be integrated into undergraduate geoscience curricula for science majors and pre-service K-12 teachers in the region.