What happens if Golurk uses "Devolution Punch" against a Basic Pokemon without any evolution cards attached?
Devolution Punch will do the damage but will not put a Basic Pokemon back into the opponent's hand.
Source: Dragons Exalted FAQ (2012-08-23), TPCi Rules Team (2012-08-23)

Relevant cards

Note: All applicable cards may not be listed below.
BW6_59
BW7_150