Brain winding

The surface of the large brain has a peculiar appearance where winding pork sausage-like ridges or elevations, so-called brain windings (one gyrus, several gyri), are bounded by deep furrows, cerebral furrows (one sulcus, several sulci).
The more developed the brain is in a mammal species, the more developed the system of brain windings. In a mouse or rat, the brain surface is completely smooth (lissencephali). In a human, gorilla or dolphin, the brain surface is strongly folded (gyrencephali).