[phakding]

I would go talk to both your team mate and your boss, in that order. I would also be very cordial and professional. Learn why the teammate took the credit or may be the boss is just mistaken. Find out the truth and then set the story straight with the boss without bad mouthing the teammate.

If this happens again, then you can be little more direct.

It would also behoove you to mention your accomplishments in passing to your boss during a casual chat in the morning while you are talking about weather or current events. Bosses for most parts don't have all the minute details of who is doing what.