Cretaceous Vertebrates from Madagascar: A Window into the Biogeographic and Plate Tectonic History of Gondwana

马达加斯加的白垩纪脊椎动物：了解冈瓦纳生物地理和板块构造历史的窗口

• 批准号: 1664432
• 负责人: David Krause
• 金额: $ 26万
• 依托单位: Denver Museum of Nature and Science
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1664432&HistoricalAwards=false
• 关键词: Cretaceous; Vertebrates; Madagascar; Window; into

Cretaceous Vertebrates from Madagascar: A Window into the Biogeographic and Plate Tectonic History of GondwanaDavid Krause, Stoneybrook, EAR-1528273Patrick O'Conner, Ohio University, EAR-1525915This proposal is jointly funded by the Sedimentary Geology and Paleobiology Program (EAR/GEO) and the Africa, Near East & South Asia Program/Office of International Science and Engineering (OD). ABSTRACTNon-technical ExplanationThe latter half of the Mesozoic Era witnessed profound changes in the configuration of landmasses that comprised the southern supercontinent Gondwana, with dramatic consequences for the associated vertebrate faunas. Madagascar lay near the center of Gondwana as it fragmented into its component parts. This proposal seeks to continue a project designed to discover and describe vertebrate fossils in a sequence of Cretaceous strata on the island, to analyze their paleobiology, to place them in phylogenetic and geologic context, and to employ them in testing biogeographic and plate tectonic hypotheses related to Gondwana as a whole and Madagascar in particular. PIs work in the Cretaceous of Madagascar is only at the very beginning of reaching its potential. To date, they 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. Many new taxa have been named and described. But much remains to be done in the vast expanses of paleontologically and geologically unexplored Cretaceous rocks of Madagascar. Many taxa are known by only fragmentary remains; many others are still to be discovered. With continued work, PIs are confident that Madagascar's Cretaceous vertebrate fauna will become one of the best known and best contextualized from the southern hemisphere and one of the primary standards against which other Gondwanan faunas of Cretaceous age are compared.Technical DescriptionPIs propose to continue collecting terrestrial and freshwater vertebrate fossils of latest Cretaceous age from the Berivotra Study Area of the Mahajanga Basin of northwestern Madagascar, which continues to produce exquisite material of poorly known taxa and specimens of new taxa. Although they have published many detailed anatomical, functional, and phylogenetic analyses of taxa known from this basin, many more have been initiated and remain to be completed (in particular, on albuloid and amiid fishes, crocodyliforms, pterosaurs, sauropod and abelisauroid theropod dinosaurs, birds and other paravian theropods, and mammals). Some of this work will entail histological sampling, thus enabling a comparative analysis of ecosystem-scale, inter-element histological variation within single vertebrate skeletons and testing of hypotheses related to possible responses and growth history adaptations of taxa that are phylogenetically constrained, but which exhibit a wide array of morphological and functional specializations. PIs also propose to continue developing newly discovered field areas in the Mahajanga Basin, which are yielding new taxa of roughly the same age but from different paleoenvironmental settings. Finally, they propose to expand their efforts into the Morondava Basin of western Madagascar, where brief expeditions in 2010 and 2012 yielded important finds and demonstrated the potential for many more from strata older than those yielding fossils in the Mahajanga Basin. Discoveries from these earlier horizons will provide a deeper temporal context with which to address biogeographic and plate tectonic hypotheses. Indeed, PIs discoveries continue to have profound implications for the biogeographic history of the extant and extinct Malagasy fauna and for the relative importance of dispersal and vicariance during Gondwanan fragmentation. One of their overarching goals is to provide a key building block for reconstructing Gondwanan biogeographic history in the form of a temporally controlled, well-sampled vertebrate fauna from the Cretaceous of Madagascar analyzed in a rigorous phylogenetic framework, and within the context of accurate paleogeographic reconstructions. It remains a priority to conduct detailed stratigraphic, sedimentologic, and taphonomic studies of all sampled horizons in order to provide temporal control as well as paleoenvironmental and paleoclimatic context. More specifically, PIs propose to conduct: (1) a comprehensive analysis of Maevarano Formation taphonomy that will provide taxonomic summaries and maps for each major quarry, and will detail the preservation of the Maevarano Formation?s exceptionally-preserved vertebrate record; (2) a comprehensive report on the geochemistry and micromorphology of exceptionally-preserved paleosols and associated fluvial sediments in the Masorobe and Anembalemba members of the Maevarano Formation, which will provide critical insights into paleoclimate; (3) a study focused on trace fossils discovered in the Maevarano Formation, specifically back-filled burrows associated with an entombed carcass (subterranean scavenging); and (4) a study clarifying and formalizing the lithostratigraphy of Upper Cretaceous horizons in the Morondava Basin.

马达加斯加的白垩纪脊椎动物：冈德瓦纳维德·克劳斯（Gondwanadavid Krause）的生物地理和板块构造历史，斯托尼布鲁克（Stoneybrook），EAR-1528273PATRICK O'CONNER，俄亥俄州大学，EAR-1525915，这一提议由Sedimimimential Geology and International Alightary Elogial and/Alightary Geolologial and/Geo sermiia and/Geo sermiia及其Arive/Geo ersiia＆Geo ersia/Geo;科学与工程（OD）。摘要中生代时代的后半段的摘要见证了构成南部超大陆冈瓦纳的地质的构型变化，对相关的脊椎动物动物群带来了巨大的后果。马达加斯加躺在冈瓦纳中心附近，因为它碎裂成其组成部分。该提案试图继续一个旨在在岛上发现和描述脊椎动物地层的脊椎动物的项目，以分析其古生物学，将其置于系统发育和地质学环境中，并雇用它们在与gondwana相关的生物地理学和板块构造假设中，尤其是整个gondwana。在马达加斯加的白垩纪工作，PIS仅在发挥其潜力的最初。迄今为止，他们已经Quintuplepulplepulple，从岛上发现了晚期白垩纪脊椎动物的多样性，并发现了一些最完整，保存得最壮观的标本，这些标本是南半球和世界上的白垩纪脊椎动物的后期标本。许多新的分类单元已被命名和描述。但是，在马达加斯加的古生物学和地质尚未探索的白垩纪岩石上，还有很多工作要做。只有碎片遗迹知道许多分类单元。许多其他人仍在发现。随着工作的持续工作，PIS有信心，马达加斯加的白垩纪脊椎动物动物区系将成为南半球最著名和最佳情境之一，这是其他标准之一，这是其他冈瓦南动物群的主要标准之一，这些标准是其他冈德瓦南动物群的白垩纪时代的动物。马达加斯加西北部的Mahajanga盆地，该盆地继续生产出鲜为人知的分类单元和新类群标本的精美材料。尽管他们已经出版了许多从该盆地所知的分类单元的解剖学，功能和系统发育分析，但已经启动并仍将完成更多的解剖学分析（尤其是在Amiid和Amiid鱼类，鳄鱼，翼龙，翼龙，翼龙，sauropod，sauropod，sauropod和Abelisauroid theropod theropod theropod pareosaurs和birds birds paravian和birds paravian the and paravian and paravian and the and the and the and the and the and the。这项工作的某些工作将需要进行组织学取样，从而对单个脊椎动物骨骼内的生态系统规模，元素间的组织学变化进行比较分析，并测试与可能受到系统性约束的分类群相关的假设和生长历史适应性相关的假设，但表现出广泛的文学和功能专长阵列。 PIS还建议继续在Mahajanga盆地开发新发现的田野区域，该地区的新分类单元的年龄大致相同，但来自不同的古环境环境。最后，他们建议将他们的努力扩展到马达加斯加西部的莫隆多瓦盆地，在2010年和2012年进行的简短探险提出了重要的发现，并证明了比在Mahajanga盆地中产生化石的地层更大的许多地层的潜力。从这些早期视野中发现的发现将提供更深层的时间环境，以解决生物地理和板块构造假设。的确，PIS发现对现存和灭绝的马达加斯加动物区系的生物地理历史以及在冈瓦南分散期间分散和替代性的相对重要性都具有深远的影响。他们的总体目标之一是为重建冈瓦南生物地理历史记录的关键构建块，其形式是从严格的系统生理框架中分析的马达加斯加of of Madagascar的时间控制，被清采样的脊椎动物动物群，以及在准确的古地理重新构造的背景下。进行所有采样视野的详细地层，沉积和taphonomic研究仍然是优先考虑的，以提供时间控制以及古环境和古气候环境。更具体地说，PIS建议进行：（1）对Maevarano组的综合分析，将为每个主要采石场提供分类学摘要和地图，并将详细介绍Maevarano形成的保存，并保留了特殊保存的脊椎动物记录； （2）一份关于泥摩虫和Maevarano组成员中特殊保存的古溶质和相关河流沉积物的地球化学和微观形态的综合报告，这将为古气候提供关键的见解； （3）一项研究的研究重点是在Maevarano组中发现的痕量化石，特别是与尸体car体（地下清除）相关的后填充洞穴； （4）一项研究阐明和形式化了莫隆多瓦盆地上白垩纪地平线的岩石地层学。