*Movie Name HELP*

Hi everyone. I have been going mad trying to find out the name of this movie i saw years ago.
All i can remember is a group of people go in this cave (with tunnels made of walls of rocks)and they come across some bones/a fossil in the wall of some kind of creature. Someone touches it, then they go explore some more. The thing comes to life and starts killing them. They have these helmets on to help with their breathing (kinda like space helmets) and wear kinda like space suits. And i specifically remember one of their tools/weapons....its a drill type thing that drills in a little bomb that explodes (must be to help with digging and finding stuff). Thats it people. Oh wait, and this lady tries to drill the thing when its attacking her but somehow drills her leg and boom she dies.
Id be really grateful if anyone out there can help me cos its buggin the hell outta me. Was an ok film, alright for its time
Thanks =)