Since the distribution was payable to the estate (by default), the estate (or you as executor of the estate) receives the Form 1099-R, with the taxable amount (usually the entire amount) reportable on the estate's income tax return, Form 1041 line 8, Other income. This Distributable Net Income distributed to the beneficiaries of the estate is passed through to the beneficiaries in box 5 of a Schedule K-1 (Form 1041) issued to each of the beneficiaries for inclusion as income on the beneficiaries' individual tax returns. The estate will get a deduction for the DNI on Form 1041 line 18 so the estate will not get taxed on the DNI.
Note that you did not receive a distribution from the IRA, the estate received the distribution from the IRA. You and your brothers are receiving distributions from the estate. The money you and your brothers receive is simply ordinary income. With respect to you and your brothers, the income retains no characteristics of having originated from an IRA and will be reported on Schedule E of your individual tax returns.
