They have the same bones only with different functions. Today’s crocodylians and toothed whales aren’t closely related at all. They last shared a common ancestor over 288 million years ago, when the forebears of reptiles and mammals parted evolutionary ways. Despite this, though, both the reptiles and mammals have jaws lined with conical teeth and a similar array of snout shapes. Despite vastly different evolutionary histories, the two groups have come to resemble each other. This phenomenon is called convergence