Within 30 days after it is the duty of the first qualifying trustee of a non-testamentary trust to take possession of the trust property he shall file in the office of the clerk of the district court in the judicial division where the trust was created a notice of his appointment as trustee, a copy of the instrument creating the trust if the trust was created by a writing, a list of the names, addresses, and dates of birth of the known living beneficiaries, a description of any possible unborn or unascertained beneficiaries, and an inventory under oath of the trust property which shall have come to his possession or knowledge.