Did you know that the hippopotamus and the dolphin are related? Yes! The hippos closest living relative are cetaceans (whales & dolphins) which they diverged from 55 millions years ago. No one would ever suspect any likeness between the two based on appearances so fossils have helped to establish this evolutionary link.
The hippo and cetaceans are thought to be alike in that they make sounds through the fatty area in the heads, both may “hear” though their jaws and they have a close blood match.
Who would have thought?!