Iowa Code § 598.3: Kind of action — joinder.

An action for dissolution of marriage shall be by equitable proceedings, and no cause of action, save for alimony, shall be joined therewith. Such actions shall not be subject to counterclaim or cross petition by the respondent. After the appearance of the respondent, no dismissal of the cause of action shall be allowed unless both the petitioner and the respondent sign the dismissal.