Collaborative Research: Reassessing Primate Origins through Digital Investigation of Eocene Fossils from the Bridger Basin, Wyoming

第一批灵长类动物的化石骨骼极其罕见，限制了我们对其生态、解剖学和进化的理解。尽管它们非常稀有，而且对于理解最终包括人类在内的生物辐射的最初步骤至关重要，但来自北美最完全已知的骨骼仍未被收集和研究，博物馆标本大部分仍埋在岩石中，需要准备。为了解决这个问题，研究小组将利用 3D 成像技术从博物馆样本和怀俄明州布里杰盆地新采集的标本中“虚拟”提取北美始新世（4800 万年前）已知的最完整的灵长类骨骼。 这些三维图像提供了独特的信息丰富的定量形态测量数据，将利用复杂的统计和数学技术，在化石和现存灵长类动物标本的大量比较 3D 数字数据集的背景下进行分析。虽然人们普遍认为这些早期灵长类动物与现存灵长类动物中马达加斯加的狐猴最为相似，但初步分析已开始表明这种观点并不完全准确。由于其完整性，布里杰骨骼提供了对这些想法进行批判性测试的证据，通过在进化背景下对早期灵长类动物的解剖结构进行详细分析，改变了对早期灵长类进化的理解。 此外，关于早期灵长类动物解剖学的新证据将允许测试相互竞争的系统发育假设，即这些始新世灵长类动物是否与类人猿（猴子、猿和人类）、链鼻类（狐猴、懒猴和夜猴）关系更密切，或者可能代表灵长类树的更原始分支。 最后，布里杰骨骼将首次详细描述这些标本的运动和位置行为，阐明灵长类动物起源和早期进化的适应性背景。 在进化背景下检查新骨骼的解剖结构将检验以下观点：几个早期灵长类谱系可能独立进化出专门的杂技跳跃，以前被认为是灵长类动物的共同特征。该项目包括五名本科生的参与；博士后学者；举办由 K-12 教育工作者、化石俱乐部和当地博物馆参与的实验室和现场研讨会； 并在可公开访问的网站 (www.morphosource.org) 上发布骨骼数字图集。 MorphoSource 允许研究人员和公众研究研究人员处理的每个骨骼的每个细节（包括原位骨骼位置）。将发布 3D 数据和其他相关图像的数字图集，提供改进的档案文档并增强所有感兴趣的个人对发现过程的参与。在这方面，该项目可以被视为未来研究的典范，因为它通过详尽、开放的研究材料文档记录其透明度。

Fossil skeletons of the first primates are extraordinarily rare, limiting our understanding of their ecology, anatomy, and evolution. Despite their rarity and central importance to understanding the initial steps in the biological radiation that ultimately includes humans, the most completely known skeletons from North America remain uncollected and unstudied, with museum specimens largely still entombed in rock and in need of preparation. To address this problem, the research team will 'virtually' extract the most complete primate skeletons yet known from the Eocene (48 million years old) of North America using 3D imaging technology for museum samples and newly collected specimens from the Bridger Basin, Wyoming. These three-dimensional images provide uniquely informative quantitative morphometric data that will be analyzed in the context of a massive comparative 3D digital dataset of fossil and extant primate specimens, utilizing sophisticated statistical and mathematical techniques. While it is generally accepted that these early primates were most similar to the lemurs of Madagascar among living primates, preliminary analyses have begun to suggest that this perspective is not entirely accurate. Because of their completeness, Bridger skeletons provide evidence allowing critical tests of these ideas, transforming understanding of early primate evolution through detailed analyses of their anatomy in evolutionary context. Additionally, new evidence on the anatomy of early primates will allow tests of competing phylogenetic hypotheses about whether these Eocene primates are more closely related to anthropoids (monkeys, apes, and humans), strepsirrhines (lemurs, lorises, and galagos), or perhaps represent a more primitive branch of the primate tree. Finally, Bridger skeletons will provide the first detailed characterization of locomotor and positional behavior in these specimens, clarifying this aspect of the adaptive context for the origin and early evolution of primates. Examining the anatomy of the new skeletons in evolutionary context will test the idea that several early primate lineages may have independently evolved specialized acrobatic leaping, previously considered to be a uniting characteristic of primates.This project includes the involvement of five undergraduate students; a postdoctoral scholar; hosting of lab and field workshops involving K-12 educators, fossil clubs, and local museums; and posting of digital atlases of skeletons on a publicly accessible website (www.morphosource.org). MorphoSource allows both researchers and the public to study every detail of each skeleton (including in situ bone positions) processed by the investigators. A digital atlas of 3D data and other related images will be published, providing both improved archival documentation and enhancing participation by all interested individuals in the discovery process. In this aspect, the project can be seen as a model for future research in its transparency through exhaustive, open-access documentation of research materials.