Doctoral Dissertation Improvement: Functional Morphology of Mammalian Sacra and Caudal Vertebrae: Implications for tail loss and positional behaviors in extinct primates

博士候选人Gabrielle Russo（德克萨斯大学奥斯汀分校），在Liza Shapiro博士的指导下，将研究灵长类动物功能形态学的进化方面的重要方面。重点将放在与无尾和直立姿势相关的特征上，这些特征对理解猿的起源、进化关系和运动很重要。尽管对猿类颅后骨骼进行了广泛的研究，但研究人员仍然面临着从化石材料中识别无尾和躯干姿势的困难，部分原因是缺乏合适的活体灵长类动物类比物进行比较。这损害了对功能性假设的测试，这些假设集中在化石记录中所代表的这些特征的进化上。本研究将从分类和形态学上多样化的哺乳动物样本中，从骶骨和尾椎的内外骨形态中确定尾长、姿势和运动的解剖学相关性，然后2)将确定的解剖学相关性应用于已灭绝的类人猿和其他灵长类动物的尾长、姿势和运动的重建。该项目将生成一个广泛的数据集，并测试关于尾巴长度、姿态和运动的明确假设。将收集5个哺乳动物目73种以上的外部形态测量数据。采用高分辨率x线计算机断层扫描技术，对18种活体灵长类动物的骶骨进行扫描，分析其骨小梁和骨皮质参数。这项研究将产生已知最大的哺乳动物骶骨CT扫描样本，这些样本将免费提供给生物人类学家、比较哺乳动物学家和临床医生。该项目还通过德克萨斯大学奥斯汀分校的一个针对第一代和少数族裔学生的项目征集实习生，为本科生提供教育和研究机会。

Doctoral candidate Gabrielle Russo (University of Texas, Austin), under guidance of Dr. Liza Shapiro, will investigate evolutionarily significant aspects of primate functional morphology. The focus will be on features related to taillessness and upright posture, features which are important in understanding ape origins, evolutionary relationships and locomotion. Despite extensive study of the ape postcranial skeleton, researchers continue to face difficulty identifying taillessness and trunk posture from fossil material, in part because appropriate living primate analogs for comparison are lacking. This has compromised testing functional hypotheses focused on the evolution of such features as they are represented in the fossil record.This study will 1) identify anatomical correlates of tail length, posture and locomotion from the external and internal bony morphology of sacra and caudal vertebrae in a taxonomically and morphologically diverse mammalian sample, and then 2) apply the identified anatomical correlates to a reconstruction of tail length, posture, and locomotion in extinct hominoids and other primates. The project will generate an extensive dataset and test explicit hypotheses about tail length, posture and locomotion. External morphometric data will be collected from more than 73 species belonging to five mammalian orders. Using high resolution X-ray computed tomography, sacra representative of 18 living primate species will be scanned in order to analyze trabecular and cortical bone parameters. This study will produce the largest known CT scan sample of mammalian sacra, which will be made freely accessible to biological anthropologists, comparative mammalogists, and clinicians. This project also provides educational and research opportunities to undergraduate students by soliciting interns though a University of Texas at Austin program that targets first-generation and minority students.