Growth, diet, thermophysiology and mobility of sauropods - Implications from bone isotope geochemistry for paleobiology and gigantism

骨骼和牙齿是脊椎动物个体生活史的宝贵档案。它们的同位素组成记录了有关生长、饮食、热生理和移动性以及气候和环境的信息。在这个项目中，每年的气候，季节性和饮食摄入量的时间序列将通过连续采样的生长增量和同位素分析的生物磷灰石的组织学和地球化学特征良好的蜥脚类动物长骨。记录的季节性氧同位素循环将用作（骨）生长的年度时间标记。定量生长曲线将计算所有主要的蜥脚类动物类群，是了解蜥脚类动物的个体发育和系统发育进化的基础。通过分析蜥脚类恐龙骨骼和牙齿以及潜在的现存和化石食用植物的碳同位素组成，将研究使蜥脚类恐龙获得和维持其巨大体重的饮食和进食策略。蜥脚类动物在从不同来源摄取食物和水时的移动性将被同位素追踪。通过分析骨骼和蛋壳的钙同位素，探讨产卵对现存和灭绝的祖龙钙代谢的影响及其作为性别替代的潜在用途。最后，镥铪同位素系统的适用性，直接放射性测年的骨骼化石将开发日期的演化，在蜥脚类动物谱系的arteritism。骨同位素地球化学将为古生物学、古生态学和有史以来最大的陆地动物蜥脚类恐龙的进化成功提供重要的新见解。

Bones and teeth are valuable archives of the life history of the individual vertebrate. They record in their isotopic composition information about the growth, diet, thermophysiology and mobility as well as climate and environment. In this project time-series of annual climate seasonality and dietary intake will be determined by serial sampling of growth increments and isotope analysis of the biogenic apatite on histologically and geochemically well-characterized sauropod long bones. The recorded seasonal oxygen isotope cyclicity will be used as annual time marker for (bone-) growth. Quantitative growth curves will be calculated for all major sauropod taxa and are fundamental for understanding the ontogenetic and phylogenetic evolution of sauropod gigantism. Diet and feeding strategies which enabled sauropods to attain and sustain their enormous body mass will be investigated by analyzing the carbon isotope composition of their bones and teeth as well as of potential extant and fossil food plants. Mobility of sauropods during food and water intake from different resources will be traced isotopically. The influence of laying eggs on the calcium metabolism of extant and extinct archosaurs and its potential use as gender proxy will be explored analyzing calcium isotopes of bones and eggshells. Finally the applicability of the lutetium-hafnium isotope system for direct radiometric dating of fossil bones will be developed to date the evolution of gigantism in the sauropod lineage. Bone isotope geochemistry will provide important new insights into the palaeobiology, palaeoecology, and evolutionary success of sauropod dinosaurs, the largest land animals ever.