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

博士候选人加布里埃尔·鲁索(德克萨斯大学奥斯汀分校)将在丽莎·夏皮罗博士的指导下，研究灵长类功能形态在进化上的重要方面。重点将放在与无尾和直立姿势相关的特征上，这些特征对于理解类人猿的起源、进化关系和运动很重要。尽管对猿类后颅骨进行了广泛的研究，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，部分原因是缺乏适当的灵长类活体类似物来进行比较。这项研究将1)从分类和形态多样性的哺乳动物样本的Sacra和尾椎的外部和内部骨骼形态中识别尾长、姿势和运动的解剖学相关性，然后将已识别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、姿势和运动的明确假设。外部形态测量数据将从五个哺乳动物目的73多个物种中收集。使用高分辨率X射线计算机断层扫描，代表18种现存灵长类物种的Sacra将被扫描，以分析骨小梁和皮质骨参数。这项研究将产生已知的最大的哺乳动物Sacra的CT扫描样本，生物人类学家、比较哺乳动物学家和临床医生将免费获得这些样本。该项目还通过德克萨斯大学奥斯汀分校的一个面向第一代学生和少数族裔学生的项目招募实习生，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.