On application of any party, the motion for judgment on the pleadings under rule 1.954, and the defenses of (1) lack of jurisdiction over the subject matter, (2) lack of jurisdiction over the person, (3) improper venue, (4) insufficiency of process, (5) insufficiency of service of process, (6) failure to state a claim upon which relief can be granted, and (7) failure to join a party under rule 1.234, whether made in a pleading or by motion, shall be determined before trial, unless the court orders that determination thereof be deferred until the trial.
Iowa. R. Civ. P. 1.455