Brain evolution in archosaurs: new implications for scaling, function, and the evolution of the modern conditions in birds and crocodilians

首龙的大脑进化：对鸟类和鳄鱼的尺度、功能和进化的新含义俄亥俄州大学劳伦斯·m·威特大脑理所当然地被认为是唯一最重要的器官，因此它的神经生物学和进化长期以来一直是生物生物学的中心兴趣。该项目研究始祖龙的大脑进化，始祖龙包括今天的鸟类和鳄鱼目动物，以及中生代的恐龙、翼龙和基础形式，目的是阐明现代状况的进化，并使用新的方法对迄今为止已灭绝的始祖龙的相对大脑大小和形状做出最准确的估计。因为化石通常只保存了硬的部分，一个主要的目标是通过重建软组织来评估已灭绝的祖龙的颅腔，这将为功能解释提供基础。假设将在现存的系统发育支架（EPB）方法的背景下进行测试，即化石组（恐龙）的现代亲属（鸟类，鳄鱼，蜥蜴）提供有关软组织与它们在骨骼上留下的特征之间关系的信息。相关的软组织（大脑，其覆盖物，神经，血管）将在现代动物中使用一系列方法进行研究，包括PI实验室开发的一种新型成像技术，以发现它们的骨骼相关性。然后将对这些特征的始祖龙化石进行调查。对数十个关键的化石标本进行CT扫描将是一个关键的工具，因为它不仅可以提供颅骨内嵌特征的数据，还可以产生3D数字数据集，从而可以自动进行高精度的测量。一种估算恐龙大脑大小和形状的新方法（GABRA：大体解剖脑区域近似）将被改进，允许使用最新的统计技术对相对大脑大小进行新的缩放研究。这些信息将被映射到始祖的谱系树上，通过与广泛的行为和生理类别进行关联，来评估大脑构象重大转变的适应性背景。许多本科生和研究生将接受技术和分析培训。这个项目是高度合作的，涉及世界各地的许多古生物学家和实验学家。广泛的放射成像将需要开发精细的成像协议、标准化分析、专业工作站和生物信息学创新来处理大量的多格式数字数据。不仅传播数据而且操纵数据的基于互联网的手段将是必不可少的，并且将与现有的生物信息学中心联系起来。考虑到K-12对所有恐龙事物的持续兴趣，这个项目将吸引的关注将为利用恐龙作为一般科学教学工具提供新的机会，预期的场所是媒体、学校或其他公共场合，以及互联网。

Brain evolution in archosaurs: new implications for scaling, function, and the evolution ofthe modern conditions in birds and crocodiliansLawrence M. WitmerOhio UniversityThe brain is justifiably regarded as the single most important organ, and thus its neurobiology and evolution have long been a central interest of organismal biology. This project studies brain evolution in Archosauria, the group including birds and crocodilians today and dinosaurs, pterosaurs, and basal forms during the Mesozoic, with the aims of shedding light on the evolution of the modern condition and using new methods to make the most accurate estimates, to date, of relative brain size and shape in extinct archosaurs. Because fossils usually preserve only hard parts, a major objective is to make assessments of the brain cavity of extinct archosaurs by reconstructing component soft tissues, which will then provide a basis for functional interpretation. Hypotheses will be tested in the context of the extant phylogenetic bracket (EPB) approach whereby the modern relatives (birds, crocodilians, lizards) of the fossil group (dinosaurs) provide information on the relationship between soft tissues and the signatures they leave on the bones. Pertinent soft tissues (the brain, its coverings, nerves, blood vessels) will be studied in the modern animals using a range of methods, including a novel imaging technique developed in the PI's lab, to discover their bony correlates. Fossil archosaurs will then be surveyed for these signatures. CT scanning of literally dozens of pivotal fossil specimens will be a critical tool in that it will not only provide data on features embedded within the skull but also will yield 3D digital datasets from which highly accurate measurements can be made automatically. A new method to estimate the size and shape of the brain in dinosaurs (GABRA: gross anatomical brain region approximation) will be refined, allowing new scaling studies of relative brain size using the latest statistical techniques. This information will be mapped onto a genealogical tree of archosaurs to assess the adaptive contexts of major transitions in brain conformation by making correlations with broad behavioral and physiological categories. Numerous undergraduate and graduate students will receive technical and analytical training. The project is highly collaborative, involving many paleontologists and experimentalists worldwide. The extensive radiological imaging will require development of refined imaging protocols, standardized analyses, specialized workstations, and bioinformatics innovations to deal with the voluminous multi-format digital data. Internet-based means of not only disseminating the data but also manipulating the data will be essential, and will take place in connection with existing bioinformatics hubs. Given the continual K-12 interest in all things dinosaurian, the attention this project will attract will provide new opportunities to use dinosaurs as tools to teach about science in general, with expected venues being media outlets, school or other public appearances, and the internet.