The Giant Head In The Ampule Room - A Graven Image Of An Alien Race?

Take this with a grain of salt. In the leaked Prometheus set pictures, you can see that the entrance outside of the ampule room is made of stone. In fact, there is a stone disc that's been pushed aside which forms a door to the entrance. Just inside the stone entrance is a biomechanical-looking entrance with what appears to be two hands with long fingers forming the biomechanical opening. My theory is that the Space Jockeys either built something or crash landed on a planet inhabited by a primitive alien race. After the Jockeys leave or die, the native aliens build a stone temple around the Space Jockey ship/construction. That giant head in the ampule room was built by the native aliens and they placed the ampules around the head in a display of worship and reverance to the Space Jockeys. The fact that the head and the entrance to the ampule room is covered in carved symbols leads me to think that a primitive alien race made them. I think the Space Jockeys are too advanced and powerful to waste their time carving giant heads and symbols into stone. Also consider the emply Space Jockey suit and helmet discovered just before the ampule room. Was a Space Jockey trapped inside the stone temple built by native aliens? My theories may prove to be way off when Prometeus premieres, but based on the the available pics and the trailer, I don't know what else to think.