The defendants in the action may answer separately, or such of them as are jointly interested in any particular parcel or parcels of land may answer jointly. No answer merely alleging the defendant's title or denying the plaintiff's title generally shall be sufficient, but every answer shall describe the particular parcel or parcels of land in or upon which the defendant claims an interest or lien, together with the nature of such interest or lien, and shall state specifically the grounds upon which such claim is based and the grounds upon which the plaintiff's title is claimed to be defective or void. The answer may contain any other allegations or provisions pertinent to the issues. Every answer shall be filed with the court administrator within the time allowed for answering the summons, unless the time be extended by agreement of plaintiff's attorney or by order of the court. Before the trial the court administrator shall make and file a certificate as to all defendants who have not answered or otherwise appeared, and such certificate shall be prima facie evidence of the facts therein stated.