Late Cretaceous Vertebrates from Madagascar: Implications for Gondwanan Biogeography

马达加斯加白垩纪晚期脊椎动物：对冈瓦纳生物地理学的启示

• 批准号: 0106477
• 负责人: David Krause
• 金额: $ 28.02万
• 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: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0106477&HistoricalAwards=false
• 关键词: Late; Cretaceous; Vertebrates; Madagascar; Implications

ABSTRACTLATE CRETACEOUS VERTEBRATES FROM MADAGASCAR:IMPLICATIONS FOR GONDWANAN BIOGEOGRAPHYDavid W. Krause, Gregory A. Buckley, Catherine A. Forster, Raymond R. Rogers, and Scott D. SampsonEAR-0106477PIs previous NSF-funded research has established the Mahajanga Basin of NW Madagascar as having some of the most complete and spectacularly preserved specimens of Late Cretaceous vertebrates from the southern hemisphere. Their discoveries have quintupled the previously known species diversity of Late Cretaceous vertebrates from the island and now include specimens of fishes, frogs, turtles, snakes, crocodyliforms, dinosaurs, birds, and mammals. More broadly, investigators involved in the Mahajanga Basin Project have elucidated the anatomy, paleobiology, and phylogenetic relationships of several vertebrate higher taxa, documented the Upper Cretaceous stratigraphy and sedimentology of the basin, provided key insights into the biogeographic origins of both the extinct and extant vertebrate faunas of the island, and shed significant new light on Gondwanan plate tectonics during the Mesozoic. Much remains to be done, however, in the vast expanses of paleontologically and geologically unexplored Cretaceous rocks of the Mahajanga Basin. It is clear that, even in the primary study area, the diversity of vertebrates remains inadequately sampled when compared to more thoroughly studied areas elsewhere in the world. Furthermore, despite the exquisite quality and completeness of the specimens of some taxa, the vast majority of species are represented by only fragmentary and isolated specimens. Finally, the unconsolidated nature of the Upper Cretaceous strata and the high annual rainfall ensures that the supply of new localities and new specimens is replenished on an annual basis. With continued work, the PIs are confident that the Mahajanga Basin vertebrate fauna will become one of the best sampled faunas of Cretaceous age and one of the primary standards against which other Gondwanan faunas are compared. The primary goals of the current proposal are to expand preliminary efforts through additional discoveries of fossil vertebrates in the still under-sampled primary field area; investigation of new field areas discovered in 1999; anatomical, functional, and phylogenetic analysis of specimens already discovered but still unstudied or only partly studied; additional elucidation of geologic context, including paleoenvironment and paleoclimate; and testing of biogeographic and plate tectonic hypotheses related to the breakup of Gondwana.

马达加斯加的抽象白垩纪脊椎动物：对冈瓦纳生物地理学的影响David W. Krause、Gregory A. Buckley、Catherine A. Forster、Raymond R. Rogers 和 Scott D. SampsonEAR-0106477PI 之前由 NSF 资助的研究已确定马达加斯加西北部的 Mahajanga 盆地拥有一些最完整且保存完好 来自南半球的晚白垩世脊椎动物标本。 他们的发现使之前已知的岛上白垩纪晚期脊椎动物的物种多样性增加了五倍，现在包括鱼类、青蛙、海龟、蛇、鳄鱼、恐龙、鸟类和哺乳动物的标本。 更广泛地说，参与马哈赞加盆地项目的研究人员阐明了几种脊椎动物高等类群的解剖学、古生物学和系统发育关系，记录了该盆地的上白垩统地层和沉积学，为该岛已灭绝和现存脊椎动物群的生物地理起源提供了重要见解，并为冈瓦纳板块提供了重要的新线索 中生代时期的构造运动。 然而，在马哈赞加盆地大片未经勘探的古生物学和地质学白垩纪岩石中，仍有许多工作要做。 很明显，即使在主要研究区域，与世界其他地方进行更彻底研究的区域相比，脊椎动物多样性的采样仍然不充分。 此外，尽管一些类群的标本质量精美且完整，但绝大多数物种仅以碎片和孤立的标本来代表。 最后，上白垩统地层的松散性质和高年降雨量确保了每年补充新地点和新标本的供应。 通过持续的工作，PI 相信，马哈赞加盆地脊椎动物群将成为白垩纪时期采样最好的动物群之一，并成为比较其他冈瓦纳动物群的主要标准之一。当前提案的主要目标是通过在仍然采样不足的主要野外区域发现更多脊椎动物化石来扩大初步努力；对1999年发现的新领域进行调查；对已发现但尚未研究或仅部分研究的标本进行解剖学、功能和系统发育分析；进一步阐明地质背景，包括古环境和古气候；以及与冈瓦纳大陆分裂相关的生物地理学和板块构造假说的测试。