Electron backscatter diffraction (EBSD) analysis of maniraptoran eggshells with important implications for microstructural and taphonomic interpretations

Electron backscatter diffraction (EBSD) is a useful tool for gathering crystallographic information from carbonate biominerals because it maps out the orientation of crystal grains very precisely. EBSD has become popular in invertebrate palaeontology but its application in vertebrate palaeontology remains limited. However, the study of fossil eggshells is a field where EBSD has wide potential applicability and provides a quantitative approach to fossil eggshell research as well as new qualitative data. Here we analyse fossil and extant maniraptoran dinosaur eggshells using EBSD analysis emphasizing four different aspects. The mapping imaging clarifies previously ambiguous characters such as squamatic ultrastructure and allows a more objective evaluation of avian and non‐avian maniraptoran eggshell. In particular, our results imply that the presence of an external zone in the manirpatoran eggshell is not diagnostic of avian eggshell. EBSD analysis can be also used for differentiating tru...

电子背散射衍射（Electron Backscatter Diffraction，EBSD）是一种从碳酸盐生物矿物中获取晶体学信息的实用工具，因其可极为精准地绘制出晶粒取向分布图。该技术目前已在无脊椎动物古生物学领域得到广泛应用，但在脊椎动物古生物学中的应用仍相对有限。不过，化石蛋壳研究却是电子背散射衍射具备广阔应用潜力的领域，该技术不仅可为化石蛋壳研究提供定量分析方法，还能提供全新的定性研究数据。本研究依托电子背散射衍射分析技术，从四个不同维度对化石及现生手盗龙类恐龙蛋壳展开分析。其成像绘图厘清了此前模糊不清的形态性状，如鳞片状超微结构，并可更客观地对鸟类与非鸟类手盗龙类蛋壳进行评估。尤为重要的是，本研究结果表明，手盗龙类蛋壳中存在的外层带，并非判定蛋壳归属鸟类的诊断性特征。电子背散射衍射分析亦可用于区分……