The Resting Breathing Rate of the Dinosaur Plateosaurus trossingensis via Conservation of Energy

Abstract

Conservation of energy is one of the foundations of science, and in this paper, we use this principle to estimate the resting breathing rate of the dinosaur Plateosaurus trossingensis (see Fig. 1). Animals produce the energy necessary for life via chemical reactions in which biomolecules (such as glucose) react with oxygen to release CO2, H2O, and energy. The metabolism is determined from the animal’s reported mass growth curve (the mass of the animal as a function of age during its juvenile growth) using a model based on conservation of energy. The metabolism reveals the rate at which oxygen is used by the animal. The efficiency of oxygen extraction is assumed to be the same as observed in modern birds (which have a very efficient “one-way” breathing modality and are direct descendants of dinosaurs). Using the estimated concentration of oxygen in Earth’s atmosphere during the Late Triassic period yields the amount of air that P. trossingensis breathed each minute. Finally, the tidal volume (the volume of air inhaled in each breath) was used to calculate its resting breathing rate. This exercise has been used in introductory and intermediate courses on thermal physics, and the students find it empowering (and fun) to be able to gain this insight into the physiology of a dinosaur.