Enamel as hardest biological tissue remains unaltered for millions of years and is therefore an excellent archive for studies on paleodiet, paleoecology, paleoclimate, paleoenvironment, biomechanical, and evolutionary studies. However, diagenetic alterations can influence such interpretations and therefore we analyzed the microstructure and composition (elemental and stable isotopic) of fossil and extant proboscidean teeth to study the extent of diagenesis in them. We report for the first time on the enamel microstructure data of the Indian elephantiformes Anancus, Stegodon, Elephas, and Palaeoloxodon besides analyzing Gomphotherium and Deinotherium from new formations. Furthermore, we compare their microstructure with those of the primitive African taxa of Moeritherium and Palaeomastodon. Our results from depth‐related elemental composition and oxygen isotope ratios of enamel phosphate and carbonate indicate no or only negligible modification. There is also a lack of age‐dependency of these minor alterations within the fossils collected from Siwaliks of the Himalayan Foreland Basin. Overall, our study indicates that diagenesis has not played any significant role on the samples studied here and are therefore well suited for chemical and paleontological studies and proxy for paleoclimate and paleoenvironment reconstruction.

中文翻译：

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过去和现在大象的牙齿：化石化的长角鲨臼齿中搪瓷的微观结构和组成及其成岩意义

牙釉质是最坚硬的生物组织，至今已有数百万年未曾改变，因此，它是古生物学，古生态学，古气候，古环境，生物力学和进化研究的极佳档案。但是，成岩作用的变化会影响这种解释，因此，我们分析了化石和现存的长鳍长牙的微观结构和组成（元素和稳定的同位素），以研究其中的成岩程度。我们报告首次对印度elephantiformes的珐琅微数据Anancus，剑齿象，亚洲象和古菱齿象亚属除了分析嵌齿象属和恐象从新的形式。此外，我们将它们的微结构与Moeritherium和Palaeomastodon的原始非洲分类群进行了比较。我们从与深度有关的元素组成以及搪瓷磷酸盐和碳酸盐的氧同位素比得出的结果表明，没有或仅有微不足道的修饰。从喜马拉雅前陆盆地的西瓦利克斯（Siwaliks）收集的化石中，这些微小变化也缺乏年龄依赖性。总体而言，我们的研究表明成岩作用在这里研究的样品上没有发挥任何重要作用，因此非常适合化学和古生物学研究，并可以替代古气候和古环境重建。