to the left of the rustboro gym
There is no Devon Corporation in Pokemon diamond. However, there is on Pokemon ruby,sapphire and emerald. It's in Rustboro City.
Mr Devon is the president of the Devon Corporation in Rustboro City it is the largest building located right by the Pokemon Gym. Mr Devon will be waiting for you at the top of the building.
You can find Devon in Mossdeep City he will give a Beldum. Note: Also works for Ruby and Sapphire.
take it to the Devon coörporation (second floor) at Rustborro city.
It is the big building in the north-west of rustboro city.
You need to go to mossdeep city and he'llgive you a beldum
yes in lilycove city
The root fossil must be brought to the Devon Coronation in Rustboro city. The fossil will then be revived into a lileep Pokemon. The claw fossil also found in emerald revives into the Anorith Pokemon.
You go to Rustboro City to the Devon Corporation, second floor. Talk to the researcher in the southeast corner.
You can capture one in the wild west of Lilycove City. It is rare. Or, if you have a Devon Scope, you might get blocked by something invisible. Use the Devon Scope, and it should be a Kecleon. There are a few around Fortree City.
In the slateport city boat dock place
There is no Celedon City in Pokemon Emerald