Abstract Calpionellids are widespread protozoans of Late Jurassic-Early Cretaceous age, typically found in Tethyan pelagic domains and related paleobiogeographic provinces. Their abundance and rapid evolution make them excellent biochronological markers as they are considered by the Berriasian Working Group of the ICS's International Subcommission on Cretaceous Stratigraphy as primary tools for fixing a GSSP to the base of the Berriasian stage (Jurassic-Cretaceous boundary). Regarding the calpionellid entire morphology studies, attempts of their chemical extraction from carbonated matrix are very scarce and, therefore, available 3-D morphologies are very limited. Hence, these microfossils are mostly studied in thin sections where they are randomly cut, leading to apparent variations among representatives of an individual taxon. Therefore, their taxonomy, phylogeny and related biozonations are still subject to divergent interpretations. This work proposes a first Computer-Assisted method for 3D-reconstruction of calpionellid loricae based on published axial sections. It also allows the simulation of all possible random cuts and to visualize corresponding apparent sections. Parametric 3D designs and restored sections can be defined (and stored) in Cartesian coordinate systems that respect the natural proportions of the studied tests. This leads to a more objective systematic paleontology of calpionellid section, a preliminary guide towards updating calpionellid phyletic relationships and biozonation schemes. Beyond calpionellids, our methodology may generate further ideas and alternative digital tools for micropaleontologists and paleontologists working on thin sections, leading to improvements in fossil determinations and taxonomical studies.

中文翻译：

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第一次计算机辅助 3D 重建calpionellid 测试（原生动物 incertae sedis）和相应的切片修复

摘要 Calpionellids 是晚侏罗世-早白垩世广泛存在的原生动物，通常发现于特提斯远洋区域和相关的古生物地理省份。它们的丰度和快速演化使它们成为极好的生物年代学标记，因为它们被 ICS 白垩纪地层国际小组委员会的贝里亚斯工作组视为将 GSSP 固定到贝里亚斯阶底部（侏罗纪-白垩纪边界）的主要工具。关于 calpionellid 整个形态研究，从碳酸化基质中进行化学提取的尝试非常少，因此可用的 3-D 形态非常有限。因此，这些微化石主要在随机切割的薄片中进行研究，导致单个分类群的代表之间存在明显差异。所以，它们的分类、系统发育和相关的生物区系仍然受到不同的解释。这项工作提出了第一种基于已发表的轴向剖面对 calpionellid loricae 进行 3D 重建的计算机辅助方法。它还允许模拟所有可能的随机切割并可视化相应的明显部分。参数化 3D 设计和恢复部分可以在笛卡尔坐标系中定义（和存储），尊重研究测试的自然比例。这导致了更客观的 calpionellid 部分系统古生物学，为更新 calpionellid 系统关系和生物区划方案提供了初步指南。除了 calpionellids，我们的方法可能会为研究薄片的微古生物学家和古生物学家提供进一步的想法和替代数字工具，