Crocodiles have a specialized valve in their heart that lets them bypass their own lungs to stay underwater longer.
The crocodilian cardiovascular system is far more complex than that of any other reptile. They utilize a unique valve called the foramen of Panizza to shunt oxygen-rich blood between two different aortas. This plumbing trick allows them to precisely control which parts of the body get oxygen during a deep dive. By bypassing the lungs, they can conserve their oxygen reserves and remain submerged for incredible lengths of time while hunting. This discovery reveals a level of biological engineering that makes crocodiles some of the most efficient predators in the water.
Roles of the foramen of Panizza and the extracardiac anastomosis in interaortic blood flow and oxygen delivery in the crocodilian heart
SSRN · 6727538
Crocodilians possess a unique dual-aortic circulation that maintains separation between systemic and pulmonary pressures while allowing flexible redistribution of blood flow during diving and other physiological states. However, the functional roles of the foramen of Panizza (FP) and the extracardiac anastomosis in regulating interaortic blood transfer and oxygen delivery remain debated, particularly regarding the direction and timing of interaortic flow and the mechanisms sustaining left aortic