Doctoral Dissertation Research: Paleoecology of Ankilitelo, Southwestern Madagascar: Implications for Late Quaternary Megafaunal Extinctions

全新世巨型动物的灭绝，包括巨型狐猴亚化石的消失，在马达加斯加几乎每个地区的亚化石遗址都有记录。来自这些地点的证据表明，物种灭绝的速度和潜在原因存在区域间差异。为了更好地了解马达加斯加的人类影响和/或环境变化，必须开发生态历史的区域记录。特别是马达加斯加西南部是一个非常重要的地区，因为它既记录了人类最早到达马达加斯加的地方，也记录了巨型狐猴亚化石的最新生存。本研究将利用微脊椎动物古生物学为马达加斯加西南部的巨型亚化石狐猴建立一个古生态框架。为了建立Ankilitelo动物群与现代马达加斯加森林之间的分类学和生态学关系，将对全新世晚期洞穴遗址Ankilitelo的亚化石组合进行研究。Ankilitelo的独特之处在于，巨型狐猴（古猿、巨狐猴和始祖狐猴）的保存与古生态相关的小型脊椎动物有关，包括灵长类动物、线虫、食肉动物、啮齿动物、蝙蝠、爬行动物、两栖动物和鸟类。该项目将是马达加斯加亚化石和现存小型脊椎动物动物群的第一次全面比较。本研究的具体目标是：记录Ankilitelo动物群的分类结构；将Ankilitelo亚化石组合与15个现代群落进行比较；利用这些比较来重建马达加斯加西南部灭绝动物群的生态群落和栖息地；通过比较Ankilitelo的古代栖息地和今天发生在该地区的栖息地，阐明马达加斯加西南部全新世发生的生态变化。这些目标将通过对比较样品的研究来实现，以促进对Ankilitelo材料的适当分类鉴定。根据分类鉴定，物种将被分配到饮食，运动，活动模式和体型类别。这些分类将用于捕捉15个现代社区和Ankilitelo的生态结构，并描述它们的栖息地。运用多元统计方法对安基利特洛和各现代社区的生态结构进行分析和比较。在Ankilitelo样品中似乎受到差异损害的壁龛将被确定并进一步探索。最近马达加斯加亚化石狐猴的消失就是威胁全球生物多样性的灭绝的一个例子。这个项目的结果将说明物种如何受到生态系统剧烈变化的影响，并将为马达加斯加的保护工作提供信息。这项研究的更广泛的影响还包括通过3D扫描Ankilitelo微脊椎动物动物群的牙列、头盖骨和后头盖骨的分类代表性样本来创建“虚拟收藏”。关于小型脊椎动物动物群的合作新工作的一个重要组成部分是为科学研究提供这些信息的数据库。这样的虚拟收藏不仅对对亚化石组合感兴趣的研究人员很有价值，而且对研究马达加斯加鲜为人知的微型动物群的生物学家也很有价值。此外，共同项目将与马达加斯加科学家和塔那那利佛大学的研究生建立合作研究。

Holocene megafaunal extinctions, which included the loss of giant subfossil lemurs, have been documented from subfossil sites in virtually every region of Madagascar. Evidence from these sites point to interregional disparities in the tempo and potential cause of the extinctions. To arrive at a better understanding of human impact and/or environmental change in Madagascar, regional records of ecological history must be developed. In particular, southwestern Madagascar is an area of great significance because it documents both the earliest arrival of humans to Madagascar, and the latest survival of giant subfossil lemurs. This study will draw on microvertebrate paleontology to develop a paleoecological framework for the giant subfossil lemurs in southwestern Madagascar. The subfossil assemblage of Ankilitelo, a late Holocene cave-site, will be investigated in order to establish the taxonomic and ecological relationships between the Ankilitelo fauna and modern Malagasy forests. Ankilitelo is unique in that preservation of giant lemurs (Palaeopropithecus, Megaladapis, and Archaeolemur) occurs in association with paleoecologically-relevant small vertebrates, including primates, tenrecs, carnivores, rodents, bats, reptiles, amphibians and birds. This project will be the first comprehensive comparison between subfossil and extant small vertebrate faunas in Madagascar. The specific objectives of this study are to: document the taxonomic structure of the Ankilitelo fauna; compare the Ankilitelo subfossil assemblage with fifteen modern communities; use these comparisons to reconstruct the ecological community and habitat of the extinct fauna in southwestern Madagascar; elucidate ecological changes that occurred in the Holocene of southwestern Madagascar through a comparison of the ancient habitat at Ankilitelo and that occurring in the region today. These objectives will be accomplished through the study of comparative samples to facilitate proper taxonomic identification of the Ankilitelo material. Based on taxonomic identifications, species will be assigned to diet, locomotor, activity pattern and body size categories. These categories will be used to capture the ecological structure of the fifteen modern communities and Ankilitelo, and describe their habitat. The ecological structure of Ankilitelo and each modern community will be analyzed and compared with multivariate statistics. Niches that appear to be differentially compromised in the Ankilitelo sample will be identified and further explored. The recent loss of the subfossil lemurs in Madagascar is an example of the kind of extinction that threatens biodiversity worldwide. The results of this project will illustrate ways in which species are affected by dramatic changes to their ecosystem, and will inform conservation efforts in Madagascar. The broader impacts of this study also include the creation of a "virtual collection" by 3D scanning a taxonomically representative sample of dentitions, crania and postcrania of the Ankilitelo microvertebrate fauna. An important component of the collaborative new work on the small vertebrate fauna is to make a database of this information available for scientific study. Such a virtual collection will not only be valuable to researchers interested in the subfossil assemblages, but also to biologists working on the poorly known microfauna of Madagascar. Additionally, the Co-PI will establish collaborative research with Malagasy scientists and graduate students at the Universite d'Antananarivo.