 |
 |
 |
||
| In most mammals, the nose opening is located near the tip of the snout. In modern dolphins, on the other hand, it is located on the top of the head, above the eyes. It is called the blowhole.
In development, the nose opening shifts from the tip of the snout (arrow in left embryo) to its position on top of the head. Ancestral whales also have their nose opening near the tip of the snout, and the shift to the forehead is documented evolutionarily by fossils. |
||||