A Study of the Thermal Physiology of the Dinosauria Through the Use of Oxygen Isotpes in the Bone Phosphate

利用骨磷酸盐中的氧同位素研究恐龙的热生理学

• 批准号: 9106660
• 负责人: William Showers
• 金额: $ 8.04万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-06-01 至 1994-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9106660&HistoricalAwards=false
• 关键词: Study; Thermal; Physiology; Dinosauria; Through

The question of whether dinosaurs lacked effective temperature control (were heterotherms) or were endothermic homeotherms has given rise to much controversy. Their reptilian character suggests heterothermy; in contrast, their rise to dominance over early mammalian stocks suggests high physiological efficiency - homeothermy. Despite much argument, the criteria considered to date do not yield a convincing answer. Such an answer may be obtained from oxygen isotope ratios in dinosaur bone. A basic premise, well substantiated, is that the isotopic composition of bone reflects two variables: the composition of the body fluids from which it was deposited, and the temperature at which deposition occurred. A second premise, also well established, is that the isotopic ratios in the body fluids of an individual are uniform at any one time. This implies that any isotopic differences in bone deposited in a given individual at any time will reflect differences in temperature. Observations to date suggest that in mammals, body temperatures vary only slightly between extremities and body core, whereas notable differences exist in heterothermic reptiles (such as the Komodo dragon). Isotopic values will be compared from extremital and body core bones selected from articulated or partially articulated dinosaur skeletons. The results will give the first direct evidence of dinosaur thermal physiology.

恐龙是缺乏有效的温度控制（是异温动物）还是吸热恒温动物的问题引起了很多争议。它们的爬行动物特征表明它们是异源性的；相比之下，它们在早期哺乳动物种群中占据主导地位表明了高生理效率——恒温。尽管有很多争论，但迄今为止考虑的标准并没有给出令人信服的答案。这样的答案可以从恐龙骨骼的氧同位素比值中得到。一个得到充分证实的基本前提是，骨头的同位素组成反映了两个变量：骨头沉积的体液成分，以及沉积发生时的温度。第二个前提也是公认的，那就是人体体液中的同位素比率在任何时候都是均匀的。这意味着在任何时间沉积在某个人体内的骨头的任何同位素差异都会反映温度的差异。迄今为止的观察表明，在哺乳动物中，四肢和身体核心之间的体温变化很小，而在异温爬行动物（如科莫多龙）中存在显著差异。将比较从铰接式或部分铰接式恐龙骨骼中选择的四肢和身体核心骨的同位素值。这一结果将提供恐龙热生理的第一个直接证据。