Doctoral Dissertation Improvement: Comparative and functional morphology of primate ungulae and distal phalanges

扁平的指甲是人类和其他灵长类动物的一个定义特征；它们是将这一目结合在一起的为数不多的特征之一。此外，有没有专门的指甲是现存的三个主要灵长类动物的区别：链鼻目动物(狐猴、懒猴和袋鼠)在每只脚的第二个脚趾上都有一个梳理毛发的爪子，眼镜蛇在第二和第三个脚趾上都有一个，而大多数类人猿没有。该项目由博士生Stephanie A.Maiolino在石溪大学William L.Jungers博士的指导下进行，旨在评估灵长类指甲和修剪爪子的起源、进化和多样性，并在广泛比较的哺乳动物环境中进行。将收集指甲和远端指骨的高分辨率数字照片和CT扫描的大型数据库。？CT扫描是一种非破坏性的方法，可以对嵌在保存下来的哺乳动物皮肤和身体中的骨骼进行采样。定量数据的分析将解释现存的远端指骨和指甲形状的功能和系统发育意义，并解释最早的灵长类化石的远端指骨的形式。祖先状态重建将被用来评估不同灵长类群体中梳理爪形的同源性和极性。这项研究将为理解灵长类起源和多样性的广泛问题提供不可或缺的信息。它将提供从有爪子的祖先到有指甲的灵长类动物的进化转变的数据，这是灵长类起源理论的主要组成部分。此外，我们还将了解灵长类动物分支中修剪爪子的极性；这对于对有争议的化石进行系统分析至关重要。最后，这项研究将有助于阐明一个经常被引用但知之甚少的灵长类动物实验的功能和系统发育意义。这个项目促进了女性研究生的教育，并提供了与其他学生合作的机会。它还包括对高中生和本科生进行3D和2D成像的培训和教育。为该项目收集的MicroCT扫描将使用免费的在线存储库共享，从而允许广泛访问以前无法获得的数据。最后，结果将在同行评议的期刊、专业会议和公开演讲中传播。

Flattened nails are a defining feature of humans and other primates; they are one of the few traits that unite this Order. Furthermore, the presence or absence of specialized nails distinguishes the three major extant primate groups: strepsirrhines (lemurs, lorises, and galagos) possess a grooming claw on the second toe of each foot, tarsiers have one on both the second and third toes, and most anthropoids have none. This project, conducted by doctoral student Stephanie A. Maiolino under the guidance of Dr. William L. Jungers (Stony Brook University), intends to assess the origin, evolution, and diversity of primate nails and grooming claws within a broadly comparative mammalian context. A large database of high resolution digital photographs and ìCT scans of nails and distal phalanges will be collected. ìCT scanning is employed as a non-destructive method of sampling bones embedded within preserved mammalian skins and cadavers. Quantitative data will be analyzed to interpret the functional and phylogenetic significance of extant distal phalanx and nail shape, and to interpret the form of the distal phalanges of the earliest fossil primates. Ancestral state reconstructions will be used to assess the homologies and polarities of grooming claw form in different primate groups.This research will supply information that is integral to the understanding of broad questions of primate origins and diversification. It will provide data on the evolutionary transition from a claw-bearing ancestor into a nail-bearing primate, a primary component of theories of primate origins. Additionally, an understanding of the polarity of grooming claws among primate clades will be gained; this is critical to systematic analyses of controversial fossils. Finally, this study will help elucidate the functional and phylogenetic implications of an often cited, but poorly understood primate trait.This project promotes the education of a female graduate student and provides opportunities for collaborations with fellow students. It also includes the training and education of high school and undergraduate students in 3D and 2D imaging. MicroCT scans collected for this project will be shared using a free online repository, thus allowing data that were previously unavailable to be broadly accessed. Finally, results will be disseminated in peer reviewed journals, professional meetings, and public talks.