Understanding the evolution of the earliest primates

了解最早的灵长类动物的进化

• 批准号: RGPIN-2016-06021
• 负责人: Silcox, Mary
• 金额: $ 2.04万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682943
• 关键词: Understanding; evolution; earliest; primates

The first members of our own Order, the Primates, appear shortly after the extinction of the non-avian dinosaurs, some 65 million years ago. In the early years of the Age of Mammals these primitive primates flourished, producing an impressive diversity of different forms. The current project seeks to better understand the processes by which primates originated and diversified from three different perspectives. ***First, fieldwork in Wyoming and Montana will seek to uncover new specimens of poorly known groups of early primates. Excavations in approximately 54 million year old deposits in the Bighorn Basin of Wyoming will seek new material of the rare Picromomyidae, a family known from only 11 specimens. This family includes one of the smallest primates ever documented (Picromomys petersonorum), which only weighed around 10g, making it a third the size of the smallest living primate. Work at Dorsey Creek Quarry, the site that has produced the best material for this elusive family, will seek to add to our knowledge of this tiny primate. Research in older deposits (~62 mya) in the Crazy Mountains Basin of Montana will also expand what we know about one of the most primitive families of primates, the Palaechthonidae. As one of the first primate groups to diversify, expanding our knowledge of this family is central to understanding the later rich diversity of our Order. Work in both locations will focus on periods of significant climate change, shedding light on how such changes can affect the mammalian fauna, which is relevant to modeling the effects of future climate change. ***Second, the largest single sample of stem primates, including more than 1500 specimens of known age, will be studied to document patterns of evolution in one family, the Microsyopidae. This large sample provides a unique opportunity to not only document evolutionary change as it happened, but to potentially explain the causes of that change. Cutting edge dental topographic methods for quantifying aspects of the tooth shape will make it possible to consider how periods of climate change related to shifting diets in this group. ***Finally, high resolution X-ray computed tomography (CT) data will be used to reconstruct endocasts (internal models of the skull which reflect brain anatomy) from fossil primates and from our close living and fossil relatives, including rodents and rabbits. This research will provide a better understanding of what is primitive for Primates in terms of the size and form of the brain, and better characterize the very earliest stages in the development of the exceptionally large human brain. ***In sum, this project aims to provide a better understanding of the early phases of primate evolution, helping to characterize the evolutionary backdrop against which humans ultimately evolved.********

大约6500万年前，我们自己命令的第一批成员，即灵长类动物。在哺乳动物的早期，这些原始灵长类动物蓬勃发展，产生了令人印象深刻的不同形式的多样性。当前的项目旨在更好地了解灵长类动物从三种不同角度产生和多样化的过程。 ***首先，怀俄明州和蒙大拿州的实地调查将寻求揭示众所周知的早期灵长类动物群体的新标本。怀俄明州大角盆地约有5400万年历史的矿床的发掘将寻求稀有的皮科剧院的新材料，这是一个仅从11个标本中闻名的家庭。 这个家庭包括有史以来最小的灵长类动物之一（Picromomys Petersonorum），它的重量仅为10克，使其比最小的灵长类动物的大小是三分之一。在为这个难以捉摸的家庭生产了最佳材料的地点Dorsey Creek Quarry的工作，将寻求增加我们对这个小小的灵长类动物的了解。蒙大拿州疯狂山区盆地旧矿床（〜62 Mya）的研究也将扩大我们对最原始的灵长类动物家族之一Palaechthonidae的了解。作为最早的多元化群体之一，扩大我们对这个家庭的了解对于理解我们秩序后来丰富的多样性至关重要。在两个地点的工作都将集中在严重的气候变化时期，阐明了这种变化如何影响哺乳动物动物群，这与建模未来气候变化的影响有关。 ***第二，将研究最大的茎灵长类动物样本，包括已知年龄的1500多个标本，以记录一个家族的Microsopidae的进化模式。这个大型样本提供了一个独特的机会，不仅可以记录其发生的进化变化，而且可以解释这种变化的原因。用于量化牙齿形状各个方面的尖端牙齿地形方法将使您可以考虑与该组中饮食转移的气候变化时期如何相关。 ***最后，高分辨率X射线计算机断层扫描（CT）数据将用于重建来自化石灵长类动物以及我们的亲密生活和化石亲属（包括啮齿动物和兔子）的内肠带（反映脑解剖结构的颅骨内部模型）。这项研究将更好地理解有关大脑规模和形式的灵长类动物的原始内容，并更好地表征了异常大脑的发展中最早的阶段。 ***总而言之，该项目旨在更好地了解灵长类动物进化的早期阶段，从而有助于表征人类最终进化的进化背景。**************************************