How many chambers does a crocodiles heart have??
Crocodiles have structurally speaking fully separated four-chambered hearts, but have strangely enough several features that allow the mixing of oxygenated and deoxygenated blood, so that the crocodile circulatory system can function as though it had a three-chambered heart. This appears to be a later addition to the originally bird-like cardiovasculatory system, since the heart first develops four fully separated chambers and only after that a hole called the foramen of Panizza develops between the left and right aortas.
