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

合作研究：评估晚白垩世生物地理对北美早期新生代生物多样性的贡献Anne Weil，Thomas Williamson，Steven Semken在这个项目中，研究人员将利用最近在新墨西哥州圣胡安盆地Kirtland组的Naashoibito成员中发现的多样化的陆地微型脊椎动物化石组合，来检验下列假设：(1)北美最新的白垩纪存在哺乳动物区系区系；(2)北美最早的新生代恢复的动物群至少部分来自目前存在的晚白垩世北美的不同省份。白垩纪末期大规模灭绝后的陆地生态系统恢复最为人所知的是对北美西部内陆的研究。这种复苏的典型特征是出现了在上一次晚白垩世时期从北美流传下来的谱系未知的哺乳动物。这可能是因为对白垩纪最新哺乳动物动物群的了解在地理上仅限于西部内陆的北部地区。通过收集这个新的南部动物群，更好地确定Naashoibito成员的年龄，并将这个新的动物群纳入现有的系统发育和生物地理数据库的分析中，研究人员将增进对最近一次大灭绝之前的生物地理因素如何促进随后陆地生态系统恢复的理解。该项目的一个次要目标是通过参与原创研究来进行本科教育，部分针对美洲原住民学生。柯特兰组出露在纳瓦霍(Dine)民族的边缘；这个项目为Dine学生提供了一个独特的机会，让他们了解这一地区的地质史和脊椎动物化石资源，以及野外和实验室研究方法。该项目的成果将被纳入该地区理科专业本科生和职前K-12教师的地球科学本科课程。

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.