Insights into Dinosaur Body Temperatures, Physiology, and Environments from Clumped Isotope Thermometry

对恐龙体温、生理和环境的洞察--成团同位素测温PI：约翰·M·艾勒研究所：加州理工学院对恐龙的第一个科学描述是在近170年前，但它们调节体温的方式仍然是一个谜。恐龙可能是类似于鸟类和哺乳动物的吸热型(“温血”)动物，也可能更类似于鳄鱼和蜥蜴等外温型(“冷血”)爬行动物，或者可能依赖于某种中间代谢策略，如“巨型体温”，即一些“冷血”动物仅通过巨大的体型就能维持较高、稳定的体温的能力。PI将使用迄今为止尝试过的最直接和最定量的测量来探索恐龙的体温，从而探索恐龙的新陈代谢。他将使用一种新的地球化学方法--“块状同位素”测温法，该方法测量含碳酸盐矿物，包括富含碳酸盐的生物磷灰石，基于13C和18O相互结合的依赖温度的有序排列或“聚集”而形成的温度。对现代哺乳动物、化石哺乳动物和众所周知的爬行动物的初步结果表明，这种方法可以重建已灭绝物种的体温，精度为1-20摄氏度。我们的研究将检查成年蜥脚类、兽脚类和鸭脚类恐龙的化石遗骸，以及共存的鳄鱼，以及类似物种的较小的幼体和侏儒标本。该项目有望首次对恐龙的体温进行精确、定量的测量；这些数据将有可能解决脊椎动物古生物学中最长期和最著名的争论之一。该项目将在加州理工学院和邻近社区大学的本科生的帮助下进行，其结果将准备好通过洛杉矶县自然历史博物馆向更广泛的公众展示。

Insights into Dinosaur Body Temperatures, Physiology, and Environments from Clumped Isotope Thermometry PI: John M. Eiler Institution: California Institute of TechnologyThe first scientific description of dinosaurs was made nearly 170 years ago, but the ways in which they regulated their body temperatures remain a mystery. Dinosaurs could have been endotherms ("warm blooded") similar to birds and mammals, or might have been more similar to ectothermic ("cold blooded") reptiles such crocodiles and lizards, or perhaps depended on some intermediate metabolic strategy, such as "gigantothermy" the ability of some "cold blooded" animals to maintain high, stable body temperatures simply through great size. The PI will explore the body temperatures, and thereby the metabolisms, of dinosaurs using the most direct and quantitative measurements attempted to-date. He will use a novel geochemical approach, "clumped isotope" thermometry, which measures the temperature at which carbonate-bearing minerals, including carbonate-rich bio-apatite, formed based on the temperature-dependent ordering, or "clumping", of 13C and an 18O into bonds with each other. Initial results on modern and fossil mammals and well understood reptiles indicate this method can reconstruct the body temperature of an extinct species with an accuracy of 1-2oC. Our study will examine fossil remains of adult sauropod, theropod, and hadrosaur dinosaurs, co-existing crocodilians, as well as smaller juvenile and dwarf specimens of similar species. This project is expected to result in the first precise, quantitative measurements of dinosaur body temperatures; these data will have the potential to resolve one of the most long standing and well known debates in vertebrate paleontology. This project will be conducted with the help of undergraduate students from Caltech and a neighboring community college, and its results will be prepared for presentation to the broader public through the Los Angeles County Natural History Museum.