A series of treadmill-based experiments at James Cook University have determined that estuarine crocodiles don’t need the diaphragmaticus muscle, also known as the “hepatic piston pump”, to breathe.
The pump, a thin, piston-like muscle, was thought to be the main breathing mechanism in crocodiles. By comparing the respiration of exercising crocodiles with functioning and disabled pumps, though, researchers showed that the muscle was not essential for breathing. Instead, the muscles of the rib cage were the primary muscles used to inflate the lungs.
Read more at James Cook University