Remarks on the evolution of the avian sternum, dinosaur gastralia, and their functional significance for the respiratory apparatus

The sternum is a central part of the avian skeleton and, among other functions, it serves as a key element of their locomotor apparatus by providing the origin site for the primary flight musculature. Understanding the evolutionary history of the sternum is critical for understanding the origin of active flight: a fundamental characteristic of one of the most diverse extant tetrapod lineages. It recently has been proposed that the sternal...