EAGER: Digital Cranial Atlas of Pachycephalosaurid Dinosaurs

热切：厚头龙类恐龙的数字颅骨图谱马克·古德温加州大学伯克利分校厚头龙类，或圆顶头恐龙，以其独特的高度膨胀的圆顶和相关的头骨装饰为特征。它们主要来自上白垩纪（1 - 6400万年前）北美西部内陆和中亚。尽管博物馆收藏的圆顶、头骨和部分头骨的样本量不断增加，但在肿头龙的学生中，关于个体变异、个体发育（生长和发育）、圆顶功能和系统（它们彼此之间的关系），仍存在相当大的不确定性和争论。边缘头类（pachycephalasaurids + ceratopsids）发育阶段的延长和后期异速生长增加了生长阶段之间的形态或形状差异，导致同一分类群的幼虫与成虫看起来非常不同。这种极端的颅骨生长轨迹模式可能模糊了进化关系，导致不确定的系统发育特征选择，并可能夸大恐龙多样性的估计，导致白垩纪末期的灭绝事件。因此，确定肿头龙颅骨的相对生长阶段是至关重要的，然后再进行比较颅骨形态学、变异、个体发生和分类学的高级分析。该项目将开始使用非破坏性高分辨率x射线计算机断层扫描（HRCT）建立北美厚头龙类恐龙的数字颅骨图谱，以：(1)确认内部和外部的生长发育模式，并确定颅骨（颅骨）个体发育（生长）变异的程度；(2)重新评估和检验相反的假设以及相关的分类学、古生物学和古生物地理学问题；(3)加强最近的组织学研究，扩大比较颅形态计量学分析；(4)通过在www.ucmp.berkeley.edu上提供数字颅骨图谱服务，推进进化生物学、古生物学、公共教育和宣传。德克萨斯大学高分辨率x射线CT设备（UTCT）的PI对选定的厚头龙头骨进行了概念验证测试扫描和有限的全扫描。本次研究将访问落基山脉博物馆、皇家安大略博物馆、皇家泰瑞尔古生物博物馆和加州大学古生物博物馆中几乎所有厚头龙物种的头骨，这些头骨反映了北美厚头龙的100%多样性。PI将使用NSF资助的设施来完成这项工作，并将开发一个更大的地理信息学项目的原型。更广泛的影响：本项目将以多种方式为更广泛的受众服务。来自加州大学伯克利分校本科生研究学徒计划（URAP）的学生将参与构建数字地图集，从而获得数字化的新技能，并从古生物学的角度直接参与科学研究。这个项目将有助于拓宽他们作为加州大学伯克利分校本科生的知识基础和研究经验。PI将监督该地图集用户指南的开发，该指南将允许高中和本科阶段的学生使用这些数据，并在为UCMP的理解科学网站开发的案例研究中使用这些数据。

EAGER: A Digital Cranial Atlas of Pachycephalosaurid DinosaursMark GoodwinUniversity of California, BerkeleyThe Pachycephalosauria, or dome-headed dinosaurs, are characterized by a distinctive highly inflated dome with associated skull ornamentation. They are known primarily from the Upper Cretaceous (100-64 million years ago) Western Interior of North America and central Asia. Despite increasing sample sizes of domes, skulls and partial skulls in museum collections, considerable uncertainty and debate persist among students of pachycephalosaurs in regard to individual variation, ontogeny (growth and development), dome function, and systematic (how they are related to one another). Morphological or shape disparity between growth stages is increased by extended neoteny and late stage allometric growth in the Marginocephalia (pachycephalosaurids + ceratopsids), resulting in juveniles that look very different from adults of the same taxa. This pattern of extreme cranial growth trajectories potentially obscures evolutionary relationships, contributes to uncertain phylogenetic character selection, and may inflate dinosaur diversity estimates leading up to the terminal Cretaceous extinction event. Thus, it is critical to identify the relative growth stage of a pachycephalosaur cranium preceding any advanced analysis of comparative cranial morphology, variation, ontogeny and systematics. This project will begin to build a digital cranial atlas of North American pachycephalosaurid dinosaurs using non-destructive high-resolution X-ray computed tomography (HRCT) to: (1) confirm internal and external patterns of growth and development and determine the extent of cranial (skull) ontogenetic (growth) variation; (2) reevaluate and test opposing hypotheses and associated taxonomic, paleobiologic, and paleobiogeographic questions; (3) enhance recent histological studies and expand comparative cranial morphometric analyses; (4) advance evolutionary biology, paleontology, public education and outreach by serving the digital cranial atlas on www.ucmp.berkeley.edu. Proof of concept test scans and limited full scans of select pachycephalosaurid skulls were confirmed by the PI at the University of Texas High-Resolution X-ray CT Facility (UTCT). Skulls of nearly all pachycephalosaurid species in the Museum of the Rockies, Royal Ontario Museum, Royal Tyrrell Museum of Paleontology, and the UC Museum of Paleontology reflecting 100% of North American pachycephalosaur diversity will be accessed for this study. The PI will be using a NSF sponsored facility to do this work and will be developing the prototype of a larger geoinformatics project.Broader Impacts: This project will serve a broader audience in multiple ways. Students from the UC Berkeley undergraduate research apprentice program (URAP) will be engaged in building the digital atlas thus gaining new skills in digitization and engaging directly in scientific research from a paleobiological perspective. This project will serve to broaden their knowledge base and research experience as a UC Berkeley undergraduate. The PI will oversee the development of a user's guide to the atlas, which will allow the data to be used by students at both the high school and undergraduate levels and within a case study to be developed for UCMP's Understanding Science website.