I dug up T-rex and triceratops skulls in Bokura wa Kaseki Holder (We are Fossil Holders). The experience is very reminiscent of Spectrobes, down to the removing the dust by blowing on the screen. In the demo I could only whack the ground with a hammer, chisel with a drill, blow dust away and scan with the orange X-ray button in the middle. Since the skull is a covered by dirt the hammer is the second tool you want to use. The X-ray should be the first since it temporarily flashes what is underground.
Once I saw an outline of the skull, I hit the ground with the hammer. Most of the impact was concentrated on the spot I tapped. A small, less powerful shockwave also removed nearby dirt. When I saw the fossil I tried to slow down and carefully remove the dirt with the drill. However, the drill was too slow. Instead I took advantage of the shockwave to remove additional layers of dirt then I pulled out the drill to finish the job. As long as you are careful where you aim the shockwaves, the fossil will should be OK. If you start to see greenish cracks, you’re damaging it. You don’t want to damage the fossils.