A new Battlefield 4 Dinosaur Easter Egg has been discovered on the Rouge Transmission multiplayer map. The secret requires that two players work together to press two different buttons on different sides of the map.
When pressed together, it will trigger an audio file that will play one of two sounds. One of them is a group of tress rustling, followed by the loud screech of a dinosaur.
The video below by Jackfrags, describes exactly how to perform the trick.