Well, in a monophylitic sense, dolphins and whales are fish... as are kangaroos and orangutans. Sarcopterygii, perhaps, but if we're not fish on that basis, the

Well, in a monophylitic sense, dolphins and whales are fish... as are kangaroos and orangutans. Sarcopterygii, perhaps, but if we're not fish on that basis, then neither are coelacanths and lungfish.