What characteristics make the whale a mammal?
Primarily descent. Whales had mammalian ancestors and, therefore, are mamamls. That’s the only qualification reality requires. This common descent is shown by the possession of traits typical of mammals, but I’ll try to contain my enthusiasm and not attempt a complete list. One of the most obvious and comprehensible ones is that Mrs Whales -assuming they’re properly married, or course- feed their babies with milk from their mammary glands, and mammals are the only extant critters to have such fine things as breasts. Whales, as with all mammals, maintain a body temperature that is higher than the external one. They do this by burning food for fuel. That character is actually also applicable for birds, but it occurred independently in both lines. Other vertebrates don’t have high body temperatures. The lower jaw of a whale is attached to its skull by a joint termed the dentary-squamosal. No other living animals have that joint apart from mammals. The lower jaw also happens to be composed
