Drache

I guess you are talking about the three Tarkeen Keys.
Once you enter the level go ahead, bus be aware of traps.
There should be a large dinosaur. It won´t harm you, if you don´t attack it.
There are some stone cubes to the left. Climb them up. Stay on guard, there are many raptors up there.

There is a small path to the left leading to a fallen tree and one Key. I guess you found that one by your own.

Return to the place where you climbed up. Go ahead and pass the walls. There are three baby Raptors and a hollow trunk close to a abyss. Kill the Raptors and go as close as possible to the edge of the abyss. If you walk along the edge looking down you should find a small ledge. Jump on it. There is a small tunnel leading inside trunk. There is a ladder which leads to another Key.

Now return to the point where you climbed up, again. There is another way to the left. Many Raptors are hanging out there. Be careful. Of course there are more traps, too. Go ahead until you approach a huge wall. The gate you open by collecting the Keys is to the left. At the wall schould be a hollow trunk lieing on the ground. Move through it and youw ill enter a room full of baby Raptors. There is the last Key.

Be careful when you pass the gate you opened. It will be closed behind you and two Sabertooth will leave the temple in front of you. Once you killed them youll be attacked by several of those strange creatures who can appear and disappear whenever and whereever they want. You have to kill all of them before you can finish the mission by entering the temple.