Since the naming of the dinosaurs in 1842 it has been thought that their metabolisms were similar to current day ectothermic, cold blooded reptiles., In the 1960’s- 1970’s; however, it started to become apparent that an endothermic metabolism (warm blooded, like mammals) is more conformable with new evidence and observations. Originally, predictions on the paleothermometry of dinosaurs was based on the physical performance such as the estimation of running speed from trace fossils as well as comparisons of fossil biomass to modern day analogues. A more accurate and unambiguous method of predicting the body temperatures of dinosaurs is through the application of clumped isotope thermometry.
Clumped isotope thermometry involves the use of heavy, …show more content…
Gillooly (2006) introduced a biophysical model based on the allometric scaling laws as well as the growth rates of many dinosaurs to predict that as mass increased, so did body temperature. This model indicated that dinosaurs were ectotherms and some of the largest sauropods had body temperatures of over 40°C. Through the use of the prior mentioned clumped isotopic thermometry, as well as the analysis of Brachiosaurus teeth from various locations it has been discovered that the internal body temperatures of these dinosaurs were roughly 38.2°C to 33.6°C. This means that the prior model implies higher average body temperatures than the results yielded from the data of this study. The results show that the average body temperatures of Sauropods are roughly 5°C to 12°C higher than temperatures previously measured from modern and fossil ectotherms (such as crocodiles and alligators). Instead, the measured temperatures are closer to those of modern day mammals and lower than those of modern day birds. These observations should not be taken as a simple indication that sauropods were endothermic (as there are many influences on body temperature); instead the results can place constraints on sauropod physiology. One possible explanation for the temperatures being lower than those predicted by Gillooly (2006) is that fully grown sauropods had mechanisms that regulated their body temperatures. A tracheal surface and air sac system that served as an internal cooling system, along with long necks and tails that facilitated heat dispersion could have been effective cooling methods that the sauropods
Clumped isotope thermometry involves the use of heavy, …show more content…
Gillooly (2006) introduced a biophysical model based on the allometric scaling laws as well as the growth rates of many dinosaurs to predict that as mass increased, so did body temperature. This model indicated that dinosaurs were ectotherms and some of the largest sauropods had body temperatures of over 40°C. Through the use of the prior mentioned clumped isotopic thermometry, as well as the analysis of Brachiosaurus teeth from various locations it has been discovered that the internal body temperatures of these dinosaurs were roughly 38.2°C to 33.6°C. This means that the prior model implies higher average body temperatures than the results yielded from the data of this study. The results show that the average body temperatures of Sauropods are roughly 5°C to 12°C higher than temperatures previously measured from modern and fossil ectotherms (such as crocodiles and alligators). Instead, the measured temperatures are closer to those of modern day mammals and lower than those of modern day birds. These observations should not be taken as a simple indication that sauropods were endothermic (as there are many influences on body temperature); instead the results can place constraints on sauropod physiology. One possible explanation for the temperatures being lower than those predicted by Gillooly (2006) is that fully grown sauropods had mechanisms that regulated their body temperatures. A tracheal surface and air sac system that served as an internal cooling system, along with long necks and tails that facilitated heat dispersion could have been effective cooling methods that the sauropods