Each such petition shall contain the name of the political subdivision appearing as petitioner therein, a description of the lands, property, and rights which the political subdivision intends to acquire, and the names and addresses of all owners and claimants thereof, including each trustee and mortgagee under each deed of trust and mortgage, if known, or a statement that they are unknown. The petition shall pray that the commission fix the just compensation which shall be paid by the political subdivision, under the law, for such lands, property and rights. The petition shall be signed in the name of the political subdivision and verified by the chairman or other presiding officer or by the secretary or clerk of the legislative or other governing body of the political subdivision. At the time the petition is filed, the petitioner shall also file with the commission additional copies thereof equivalent in number to three more than the number of owners and claimants named in the petition.