Dissertation Research: Shinisauria (Squamata, Reptilia) and Anguimorph Evolution

论文研究：Shinisauria（有鳞目、爬行动物）和 Anguimorph 进化

• 批准号: 0408064
• 负责人: Paul Sereno
• 金额: $ 0.59万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0408064&HistoricalAwards=false
• 关键词: Dissertation; Research; Shinisauria; Squamata; Reptilia

Guangxi Province of southern China is the last bastion of an extraordinary group of animals known as crocodile lizards. Today, there is only one living member of this group, yet it stretches back to the time of the dinosaurs. Preliminary anatomical study indicates that members of this group have remained virtually unchanged for at least 50 million years (Ma). Anatomy of the crocodile lizard has been very poorly known because this endangered species is extremely rare in zoological and museum collections. Previous studies of the skeleton were fraught with errors because of the poor quality of available specimens. This, coupled with the complete absence of fossils younger than the Cretaceous (65 Ma), has made it very difficult to place this group on the family tree of lizards. Fortunately, 15 complete specimens from the University of Florida and the Field Museum of Natural History (FMNH) in Chicago, Illinois will make the skeletal anatomy of this strange creature accessible to science. The current project will describe skeletal anatomy and anatomical changes between hatchling and adults and correct current misconceptions regarding the anatomy of crocodile lizards. Changes in anatomybetween newborn and adults also will be described in related lizards. Additionally, FMNH recently acquired a fossil from Wyoming representing the first known fossil crocodile lizard younger than the Cretaceous. Preliminary work indicates that the new fossil is all but identical to the living form. This is significant because of the age of the fossil (about 50 Ma) and the distance separating the two species (living crocodile lizards come only from East Asia, whereas the fossil is from the western United States). This project will describe and name the new fossil form and develop a new systematic analysis to place it on the family tree of lizards. These data will then be used to address the great anatomical similarity between the fossil and the living form, which is properly regarded as a "living fossil." Understanding the placement of any animal group on the tree of life is central to studying evolutionary processes (such as long-term persistence of anatomical forms, as evidenced by crocodile lizards) and to developing hypotheses about the origin and history of biological diversity. Additionally, the new family tree will be used to compare the occurrences of crocodile lizards to other groups with similar distributions. For example, several groups of fossil and living fishes exhibit remarkably similar distributions, which means that the study of crocodile lizards may become broadly significant to interpreting the history of the western North American and Asian landmasses. Broader impacts of this study include: 1) training of a doctoral student in vertebrate anatomy and systematics; 2) the first detailed anatomical study of the crocodile lizard, a globally endangered species that has been very poorly studied up to now and that has excellent potential to attract broad public interest in science and global change because of its rarity and interesting fossil record; 3) description and naming of a remarkable new and important fossil species; 4) dissemination of research findings via scientific publications, lectures and websites; 5) inclusion of 3-dimensional images of crocodile lizards on the Digital Morphology Website at the University of Texas (http://www.digimorph.org/index.phtml; note that this site attracts a great deal of interest from non-scientists because of its arresting 3-D images of animal skeletons based on cat-scanning technology); 6) training of inner-city high school students in Chicago through BioOutreach and Project Exploration, two programs designed to excite student interest in science and augment their regular classroom experiences.

中国南部的广西省是鳄鱼蜥蜴这一特殊动物群体的最后堡垒。今天，这个群体只有一个活着的成员，但它可以追溯到恐龙时代。初步的解剖学研究表明，这个群体的成员几乎保持不变，至少有5000万年（Ma）。鳄蜥的解剖学一直知之甚少，因为这种濒危物种在动物学和博物馆收藏中极为罕见。 由于现有标本的质量差，以前对骨骼的研究充满了错误。 这一点，再加上完全没有比白垩纪（65 Ma）更年轻的化石，使得很难将这个群体放在蜥蜴的家谱上。 幸运的是，来自佛罗里达大学和伊利诺伊州芝加哥菲尔德自然历史博物馆（FMNH）的15个完整标本将使这种奇怪生物的骨骼解剖学成为科学。 目前的项目将描述骨骼解剖学和解剖学之间的变化幼雏和成人和纠正目前的误解有关鳄鱼蜥蜴的解剖。 新生儿和成年蜥蜴之间的解剖结构变化也将在相关蜥蜴中描述。 此外，FMNH最近从怀俄明州获得了一块化石，代表了第一个已知的比白垩纪更年轻的鳄鱼蜥蜴化石。 初步工作表明，新化石与活化石几乎完全相同。这一点很重要，因为化石的年龄（大约50 Ma）和两个物种之间的距离（活的鳄鱼蜥蜴只来自东亚，而化石来自美国西部）。 该项目将描述和命名新的化石形式，并开发一个新的系统分析，将其放置在蜥蜴的家谱。 这些数据将被用来说明化石和活体之间的巨大解剖学相似性，这被正确地视为“活化石”。“了解任何动物群体在生命树上的位置对于研究进化过程（例如解剖形式的长期持续性，如鳄鱼蜥蜴所证明的）以及发展关于生物多样性起源和历史的假设至关重要。 此外，新的家谱将用于比较鳄鱼蜥蜴与其他具有类似分布的群体的发生情况。例如，几组化石和活鱼显示出非常相似的分布，这意味着鳄鱼蜥蜴的研究可能对解释北美西部和亚洲大陆的历史具有广泛的意义。 这项研究的更广泛的影响包括：1）培训了一名脊椎动物解剖学和系统学博士生; 2）首次对鳄鱼蜥蜴进行了详细的解剖学研究，鳄鱼蜥蜴是一种全球濒危物种，迄今为止研究得很差，由于其稀有性和有趣的化石记录，它具有吸引公众对科学和全球变化的广泛兴趣的巨大潜力; 3）描述和命名一个引人注目的新的和重要的化石物种; 4）通过科学出版物、讲座和网站传播研究成果; 5）在德克萨斯大学的数字形态学网站上收录鳄鱼蜥蜴的三维图像（http：//www.digimorph.org/index.phtml;请注意，该网站吸引了非科学家的极大兴趣，因为其基于猫扫描技术的引人注目的动物骨骼三维图像）; 6）通过生物外展和项目探索培训芝加哥市中心的高中学生，这两个项目旨在激发学生对科学的兴趣，增加他们的常规课堂经验。