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东海残留沉积区舟山ＱＺ５０４孔未发现上海地区普遍存在的全新世暗绿色硬粘土层。但通过对该孔微体古生物组合特征的分析与对比，划分了全新世与更新世的更线，反映了气候的变化，证实了滚流对本区的影响。 相似文献
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从更广泛和较高的层次对地质时期地球表层的生命活动和环境变化进行多学科的综合性研究，在全球系统分析的基础上为“协调人类与自然关系”的战略主题提供决策依据。以高分辨率地层学框架的研究的基础，综合多种学科对事件、间事件及其载体和介质的定量研究，为生物与环境的耦合机制的认识及有关模式的建立提供科学依据。化石燃料作为事件产物，其分布规律亦为重要研究内容之一。 相似文献
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Sebastin Apesteguía 《Gondwana Research》2007,12(4):533-546
A study of the abundant and undescribed isolated and associated bones and teeth from the La Amarga Formation (Barremian of Neuquén, Argentina) permitted the recognition of additional clades of sauropod dinosaurs: basal titanosauriforms, both basal and derived titanosaurs, and rebbachisauroid diplodocoids, which are now added to the already known dicraeosaurids and a recently published basal diplodocoid. These forms substantially increase the knowledge on the Early Cretaceous sauropod diversity in Gondwana. 相似文献
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Cretaceous strata in Alabama and Mississippi (USA) represent one of the most complete records of shallow marine deposition worldwide for the Upper Cretaceous. The age assignment of these strata in the eastern Gulf Coastal Plain is difficult due to the comparative lack of radiometrically datable beds and sometimes conflicting results of biostratigraphy using different taxonomic groups. Numerical age dating using strontium isotope ratios (87Sr/86Sr) preserved in diagenetically resistant fossil shark tooth enameloid had been proposed by previous researchers as a solution to dating some geologic units. Here we apply this methodology to the whole Upper Cretaceous, using teeth of two fossil shark genera (Scapanorhynchus and Squalicorax) collected from variable facies. Shark teeth collected from a bentonite mine in Monroe County, Mississippi, were also analyzed and compared with the radiometric date of the bentonite layer. Results indicate a strong correlation between stratigraphic position of the fossil teeth and numerical age determination based on 87Sr/86Sr content. Furthermore, this method is equally effective for both of the fossil shark genera analyzed in the study. Because of the nearly uniform distribution of strontium in ocean water, numerical age dating using strontium isotope ratios preserved in fossil shark tooth enameloid can be a useful method to employ in the correlation of marine geological strata on both regional and global scales. 相似文献
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A recently discovered articulated partial skeleton of Ornithomimus from the Upper Cretaceous Dinosaur Park Formation of Alberta, Canada is remarkable in the extent and quality of preservation of integumentary structures including feathers. It is the first ornithomimid to preserve a tail bearing extensive plumaceous feathers that are slightly more elongate in comparison to those present on the remainder of the body. However, the underside of the tail and the hind limb distal to the middle of the femur appear devoid of plumage. Overall, the plumage pattern in Ornithomimus is similar to that of Struthio camelus (ostrich) and other large palaeognaths, indicating a probable function in thermoregulation. The specimen also preserves the body outline around the legs, including a skin contour anterior to the femur, analogous to skin webs in extant birds. Whereas the knee web of birds bridges the knee to the abdomen, in Ornithomimus it spans from the mid-femoral shaft to the abdomen, and is herein referred to as an anterior femoral web. This is the first report of such soft tissue structures in non-avian theropods. It may indicate that the resting position of the femur was positioned more anteroventrally in ornithomimids than in most theropods, and in that sense may have been transitional to the situation in modern birds. 相似文献
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冲绳海槽D－086孔颗石藻化石及其古海洋学意义的初步探讨 总被引：2，自引：0，他引：2
本文通过对冲绳海槽Ｄ－０８６孔颗石藻化石的研究，自下而上划分出三个颗石藻化石组合：Ｇｅｐｈｙｒｏｃａｐｓａａｐｅｒｔａ－Ｇ．ｏｃｅａｎｉｃａ组合，Ｇｅｐｈｙｒｏ－ｃａｐｓａｅｒｉｃｓｏｎｉｉ－Ｃｏｃｃｏｌｉｔｈｕｓｃｒａｓｓｉｐｏｎｓ组合，Ｅｍｉｌｉａｎｉａｈｕｘｌｅｙｉ－Ｇｅｐｈｙｒｏｃａｐｓａｏ－ｃｅａｎｉｃａ组合；划分出Ｅ．ｈｕｘｌｅｙｉ带和Ｅ．ｈｕｘｌｅｙｉ高峰带的界线；每一个颗石藻化石组合代表一个气候期，它们分别与标准气候期的玉木亚间冰期，晚玉木冰期和冰后期相当。 相似文献
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随着互联网与信息技术的快速发展,线上线下混合式学习逐渐得到普及与应用。混合式学习强调学生的主体作用,注重学生的自主学习、协作学习和个性化学习,是良好的适合高等教育的创造性学习模式。但是在目前的混合式学习模式下,学生对知识的加工、梳理、整合能力不够,构建完整知识体系的自主学习能力稍显薄弱,因此亟需更多引导。文章综合分析了混合式学习模式的优缺点,建议引入人工智能领域的知识图谱概念,作为新的教学元素以引导和加强学生的自主学习过程,由此构建了基于知识图谱的增强型混合式学习模式。该模式在2020年南京大学《古无脊椎动物学》课程中进行了实践,进一步证明其在改善学生自主学习能力方面的潜力。 相似文献
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贵州瓮安磷矿新元古代微体生物化石 总被引：2，自引：0，他引：2
发现于新元古代陡山沱期的瓮安生物群是一个重要的化石生物群。它的大部分化石保存了较完好的细胞结构、组织分化特征和其他微细构造 ,经描述的属种超过 5 0个。初步研究揭示出地球早期生命漫长的进化过程 ,在距今 6亿年前就已经出现了许多高级后生生物。对瓮安生物群的深入研究将有助于进一步了解早期生命的起源和演化过程。 相似文献
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地层古生物研究工作对促进基础地质发展,指导矿产勘查等具有十分重要的意义。近年来山东省地质科学研究院通过对全省地层古生物化石研究,在生物地层、年代地层方面取得了重要进展;通过开展全国古生物化石保护工程规划研究、山东省重要古生物化石保护规划研究、胶莱盆地白垩纪脊椎动物化石保护、开发方案与规划研究等,为古生物化石保护、开发规划及其编制提供了科学依据;通过对济南、临沭、诸城、莱阳、临朐、莒南等地质公园古生物化石的调查研究,为地质公园的科学定位、科学研究、科学普及以及地学旅游发展提供了重要的科学指导,对推动社会经济可持续发展起到了支撑作用;通过开展地层古生物研究,为相关的地质找矿工作提供了基础理论依据;通过以上工作,为山东省培养了一批地层古生物人才,建立了一支技术过硬、力量雄厚、结构合理的专家团队。 相似文献