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

恐龙是否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大争议。它们爬行动物的特征表明它们具有异温性；相比之下，它们对早期哺乳动物种群的优势地位表明了高生理效率-恒温性。尽管有许多争论，但迄今为止考虑的标准并没有产生令人信服的答案。这样的答案可以从恐龙骨骼中的氧同位素比率中得到。一个得到充分证实的基本前提是，骨骼的同位素组成反映了两个变量：沉积它的体液的组成，以及沉积发生的温度。第二个前提也得到了很好的证实，即个体体液中的同位素比例在任何时候都是一致的。这意味着，在任何时候，一个特定个体体内沉积的骨骼的任何同位素差异都会反映出温度的差异。到目前为止的观察表明，哺乳动物的体温在四肢和身体核心之间只有微小的差异，而在异温爬行动物(如科莫多龙)中存在显著的差异。将比较从关节恐龙骨架或部分关节恐龙骨架中选择的四肢和身体核心骨骼的同位素值。这一结果将为恐龙热生理学提供第一个直接证据。

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.