Project B3: Respiration
|Title||Functional morphological test of the hypothetical structure of a sauropod respiratory system|
|Principal Investigator||Prof. Dr. Steve Perry|
|Researchers||Dr. Jonathan Codd, Thomas Breuer|
Through phylogenetic bracketing between crocodiles and birds it is possible to derive a minimum consensus lung, that applies to all archosaurs, living or extinct. Additional information from embryological and palaeontological sources as well as consideration of functional anatomical and physical constraints allows formulation of more precise hypotheses regarding the lung structure of dinosaurs. This project focuses on at least limited testing of these hypotheses in sauropod dinosaurs. Prosauropods, theropods and basal ornithischians will be used as fossil outgroups, crocodiles and ostriches will serve as living ones. The main hypothesis is that the sauropod respiratory system possessed some special attributes that allowed them to maintain high metabolic rates.
Existing dinosaur respiratory models rely upon a combination of data from extant species to recreate the lung structure, and upon re-construction of the estimated plane of rib movement in articulated specimens to estimate tidal volume. This project develops methods for refining and testing hypotheses about lung anatomy. First, the differential movement of individual ribs will be based on rib articulations in original specimens, rather than in partially reconstructed, mounted ones. We assume that the regions of highest compliance in the lung (sac-like structures) will correlate with the region of maximum mobility of the ribs. Thus the heterogeneity of lung structure can be estimated. Second, detailed analysis of the tendon insertions of intercostal muscles will provide information on the biomechanics of inspiratory and expiratory effort and therefore also on the intrinsic elasticity of the lungs. This parameter relates directly to the presence of high-compliance airsacs.