Earth works, structures or everyday items (including bodies or fires) left behind by these early people.
We learn that archeologists dig up fossils and they can determine what year it came from, etc.
Archeologists, paleontologists.
Excavation or "dig"
Trapinch learns Dig at level 29 in X and Y. In Omega Ruby and Alpha Sapphire, it can learn Dig as early as level 19.
archeologists dig up and examine artifacts, tools, paintings, weapons, buildings and household items.
Generally, historians do not actually dig in the ground for artifacts. Archeologists do that and inform historians of the their findings.
In Pokemon FireRed and LeafGreen, Diglett can learn Dig at level 17, which is a nice and early level for a good move.
Linoone can learn Dig by using the TM Dig. It cannot learn Dig by leveling up.
Yes, it can learn Dig by teaching it with the TM Dig. It cannot learn Dig by leveling up.
Camerupt can learn Dig by using the TM Dig. It cannot learn Dig by leveling up.
Yes, Lucario is able to learn Dig. It can learn it through the use of the Dig TM.
Yes, Numel can learn Dig, but it can only learn Dig by using the TM and not by leveling up.