Thermoregulation
Circulation
Respiration


Large animals have very low surface area to volume ratios, so they could not rely on heat diffusion through their skin to regulate their body temperatures. Therefore, they must have had independent means of adapting to fluctuations in the temperatures of their environments. Otherwise, they would overheat in the summer, which is the fate that many scientists believe befell the dinosaurs, had they not been homeotherms (Cloudsley-Thompson, 1977).