It looks like you have to do the following:
As soon as you enter, turn right, take box, open it and take the Maya scroll. Go forward once, turn left and pick up Giza skull #3 from bottom shelf. Go to the opposite wall and pick up Easter Island skull #3. Look at the skull puzzle at middle wall.
Then you position the skulls properly on the middle wall - there are pictures of this to help you in the walkthrough.
Lastly, the walkthrough says:
The skulls move to make an opening. Enter through the opening. Pick up Atlantis skull #3. Look close at the circular carving with a skull at the center. Looks familiar! Zoom in on the gold glyphs at its round points, from bottom left to bottom right: Stonehenge, Atlantis, Maya, Devil's Triangle, Giza and Easter Island. Exit the room.
I can see that you really have to be thorough in this game, as it would be easy to miss something. I think I know why I never played this game - it looked too complicated.