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

第一灵长类动物的化石骨骼非常罕见，限制了我们对它们的生态学、解剖学和进化的了解。尽管它们很罕见，而且对了解生物辐射的最初步骤至关重要，最终包括人类在内，但来自北美的最完整的已知骨骼仍然没有收集和研究，博物馆标本大多仍埋在岩石中，需要准备。为了解决这个问题，研究小组将利用3D成像技术，从怀俄明州布里杰盆地的博物馆样本和新收集的标本中提取北美始新世(4800万年前)迄今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，这些数据将在化石和现存灵长类标本的大规模比较3D数字数据集的背景下进行分析，利用复杂的统计和数学技术。虽然人们普遍认为，在现存的灵长类动物中，这些早期灵长类动物与马达加斯加狐猴最相似，但初步分析开始表明，这种观点并不完全准确。由于它们的完整性，布里杰骨骼提供了证据，允许对这些想法进行关键测试，通过在进化背景下对它们的解剖进行详细分析，改变了对早期灵长类进化的理解。此外，早期灵长类动物解剖学上的新证据将允许测试相互竞争的系统发育假说，即这些始新世灵长类动物是否与类人猿(猴子、猿和人类)、链鼻目动物(狐猴、百合花和Galagos)关系更近，或者可能代表灵长类树更原始的分支。最后，Bridger骨骼将提供这些标本中运动和位置行为的第一个详细特征，澄清灵长类起源和早期进化的这一适应背景。在进化的背景下研究新骨骼的解剖学将检验几个早期灵长类血统可能独立进化出专门的杂技跳跃的想法，这之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参与；一名博士后学者参与；主办实验室和实地研讨会，涉及K-12教育工作者、化石俱乐部和当地博物馆；以及在可公开访问的网站(www.morosource.org)上发布骨骼的数字地图集。MorPhoSource允许研究人员和公众研究由研究人员处理的每个骨骼的每一个细节(包括就地骨骼位置)。将出版3D数据和其他相关图像的数字地图集，既提供改进的档案文件，又加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，其透明度是通过详尽、开放的研究材料文件编制的。

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.