OK first you have to go to rustboro city and go in the company(dont remember name) then go to the second floor and talk to the scientist in the bottom right. go down stairs and then go back up, talk...
go to underground and click on treasures. click on the fossil and send it to bag. take it to mining museum in oberough city. give it to the creepy nerd and go outside. go back in and talk to nerd...
dig underground under any city then when you find a fossil take it to the coal museum in oreburgh. there will be a man in a white coat who will take the fossil and bring it to life to a level 20...