Whenever a husband and wife are joint tenants in the same real estate, either together or in conjunction with others, a divorce or dissolution of the marriage, unless the divorce decree or decree of dissolution otherwise provides, severs their interests and converts them into tenants in common as to each other but not as to any remaining joint tenant or joint tenants. Such severance does not become effective as to any other persons until a certified copy of the decree or abstract of it, indicating the effective date of the divorce or dissolution, has been recorded in the land records of the town where the real estate is located.