Teamwork Feats (Ex): At 4th level and at 12th level, a twinned summoner gains a bonus teamwork feat. He must meet the prerequisites of the selected teamwork feat. The twinned summoner automatically grants all of his teamwork feats to his eidolon. The eidolon doesn’t need to meet the prerequisites of these teamwork feats.
This ability replaces shield ally and greater shield ally.