The Mahajanga Basin Project: Late Cretaceous Vertebrates from Madagascar and Their Implications for the Biogeographic History of Gondwana

马哈赞加盆地项目：来自马达加斯加的白垩纪晚期脊椎动物及其对冈瓦纳生物地理历史的影响

• 批准号: 0446488
• 负责人: David Krause
• 金额: --
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0446488&HistoricalAwards=false
• 关键词: Mahajanga; Basin; Project; Late; Cretaceous

The face of the Earth changed radically during the Late Jurassic and Cretaceous. It is during this interval that the southern supercontinent Gondwana fragmented into isolated landmasses, with dramatic consequences for the associated terrestrial and freshwater vertebrate (backboned) animals. Reconstructions of the timing and sequence of this fragmentation are based almost entirely on geophysical evidence and remain poorly tested on the basis of terrestrial and freshwater vertebrate fossils. This proposal seeks to continue and expand a project designed to discover vertebrate fossils in Upper Cretaceous strata (approximately 65 million years old) of the Mahajanga Basin in northwestern Madagascar, to place them in phylogenetic, stratigraphic, and sedimentologic context, and to employ them in testing biogeographic and plate tectonic hypotheses relating to Gondwana as a whole and Madagascar in particular. The Mahajanga Basin Project was initiated over a decade ago but is only beginning to reach its potential. To date, PIs have quintupled the previously known species diversity of Late Cretaceous vertebrates from the island and have discovered some of the most complete and spectacularly preserved specimens of Late Cretaceous vertebrates from the southern hemisphere and, indeed, the world. But sampling is clearly incomplete and much remains to be done in the vast expanses of paleontologically and geologically unexplored Cretaceous rocks of the Mahajanga Basin. With continued work, PIs are confident that the vertebrate fauna from the Cretaceous of the Mahajanga Basin will become one of the best sampled and best known faunas of Cretaceous age from the southern hemisphere and one of the primary standards against which other Gondwanan faunas of Cretaceous age are compared. The discovery and rigorous phylogenetic analysis of additional and more complete vertebrate fossils from Upper Cretaceous horizons in the Mahajanga Basin of northwestern Madagascar, and their placement in geological context, will: 1) shed significant new light on the diversity and evolutionary history of vertebrates from the southern supercontinent of Gondwana in general and Madagascar in particular, and 2) permit tests of competing hypotheses about the physical and biotic connections of the component parts of Gondwana during the Mesozoic and serve to elucidate the biogeographic origins of the highly endemic extant vertebrate fauna of Madagascar, arguably one of the greatest unsolved mysteries of natural history. As in the past, this project is firmly committed to providing a training ground for both Malagasy graduate students and for American high school, undergraduate, and graduate students, as well as postdoctoral associates. Also as in the past, results of this project will be disseminated to both the scientific community and the general public in a variety of ways including original publication, media exposure, the internet, museum displays, and lectures/seminars. PIs will also continue their efforts to build schools and provide healthcare for children living in remote areas of Madagascar through an organization, the Madagascar Ankizy Fund (www.ankizy.org), that they established in 1998.

地球的面貌在晚侏罗世和白垩纪发生了根本性的变化。 正是在这段时间里，南部的冈瓦纳超大陆分裂成孤立的陆块，对相关的陆地和淡水脊椎动物（脊椎动物）造成了巨大的影响。 重建的时间和顺序的这一分裂几乎完全是基于地球物理证据和仍然缺乏测试的基础上陆地和淡水脊椎动物化石。 该提案旨在继续和扩大一个项目，旨在发现马达加斯加西北部马哈赞加盆地上白垩纪地层（约6500万年）中的脊椎动物化石，将其置于系统发育、地层和沉积学背景中，并将其用于检验与整个冈瓦纳大陆，特别是马达加斯加有关的地理和板块构造假说。 Mahajanga盆地项目于十多年前启动，但才刚刚开始发挥其潜力。 到目前为止，PI已经将岛上晚白垩世脊椎动物的物种多样性增加了五倍，并发现了一些来自南半球甚至是世界上最完整和保存最完整的晚白垩世脊椎动物标本。 但是，采样显然是不完整的，还有很多工作要做，在广阔的古生物学和地质学未经勘探的白垩纪岩石的马哈赞加盆地。 通过继续开展工作，专业研究人员有信心，马哈赞加盆地白垩纪的脊椎动物群将成为南半球白垩纪最佳采样和最知名的动物群之一，并成为与其他白垩纪冈瓦纳动物群进行比较的主要标准之一。 在马达加斯加西北部马哈赞加盆地上白垩纪地层发现更多更完整的脊椎动物化石，并对其进行严格的系统发育分析，以及将其置于地质背景中，将：1）揭示了冈瓦纳南部超级大陆，特别是马达加斯加的脊椎动物的多样性和进化历史，和2）允许测试有关冈瓦纳大陆的组成部分在中生代的物理和生物连接的竞争假设，并有助于阐明马达加斯加高度特有的现存脊椎动物群的地理起源，可以说是自然历史上最大的未解之谜之一。 与过去一样，该项目坚定地致力于为马达加斯加研究生和美国高中，本科生和研究生以及博士后提供培训基地。 与以往一样，该项目的成果将以各种方式向科学界和公众传播，包括原始出版物、媒体曝光、互联网、博物馆展览和讲座/研讨会。 公共利益机构还将继续努力，通过它们于1998年设立的马达加斯加Ankizy基金（www.ankizy.org），为生活在马达加斯加偏远地区的儿童建造学校和提供保健。