Systematics, Zoogeography and Phylogenetics of Skates (Chondrichthyes, Rajoidei)

这项建议是要求资金继续长期 系统分类、分布及演化研究 冰刀和鳐的关系（扁平软骨 鱼类）。 研究的总体目标是澄清 亚属内部和亚属之间的进化关系， 冰鞋的种类，使用这些信息来构建 冰鞋的分布和进化模式， 推测冰鞋的进化关系， 其他种类的射线（锯鳐，吉他鱼，电射线和 刺鳐）。 具体而言，拟议的研究将：1）测试， 在必要时详细阐述和修订目前的假设， 冰鞋的进化关系 头骨，鳃弓，肩带，骨盆带， 所有亚属和亚属的内陷器官和牙齿形态 属和大多数物种;和2）比较这些 结构，鳃弓肌肉组织，颅神经， 冰鞋头部和鳃弓血管与其他 射线 对冰鞋的详细系统和进化研究 在过去的30到40年里， 对冰鞋进行了全面深入的进化研究。 这些 研究已经澄清了大多数物种水平的系统 问题，并承认大多数亚属和属。 然而，进化关系仍然不确定。 成功完成拟议的研究将有助于： 1)阐明生物多样性和生物多样性的进化相互关系 软骨鱼类（银鲛、鲨鱼和鳐）; 2） 了解底栖鱼类的分布模式; （3）了解一个多样化但 形态上保守的生物群。

This proposal is a request for funds to continue a long term study on the systematics, distribution, and evolutionary relationships of skates and rays (flattened cartilaginous fishes). The overall objectives of the study are to clarify the evolutionary relationships within and among the subgenera and genera of skates, to use this information to construct distributional and evolutionary patterns for skates, and to speculate on the evolutionary relationships of skates and the other taxa of rays (sawfishes, guitarfishes, electric rays and sting rays). Specifically, the proposed research will: 1) test, elaborate and revise as necessary the current hypothesis of evolutionary relationships of skates by comparative analysis of the skull, gill arches, shoulder girdle, pelvic girdle, intromittent organs, and tooth morphology of all subgenera and genera and a majority of the species; and 2) compare these structures, and the gill arch musculature, cranial nerves, and head and gill arch blood vessels of skates with those of other rays. Detailed systematic and evolutionary studies of skates over the past 30 to 40 years have set the stage for a comprehensive and in-depth evolutionary study of skates. These studies have clarified most of the species level systematic problems and recognized most of the subgenera and genera. However, the evolutionary relationships remain uncertain. Successful completion of the proposed study will contribute to: 1) clarification of the evolutionary interrelationships of the cartilaginous fishes (chimaeras, sharks and rays); 2) the understanding of the distributional patterns of benthic fishes; and 3) knowledge of the evolutionary patterns of a diverse but morphologically conservative group of organisms.