The Neolithic site of Ibn Hamuda (Phase II) found on the Yemen-Oman border, stretches for over 1 km. along a now fossilized river system leading into the Rub al Khali. This site has yielded an enormous number of pounders, abraders, pestles, and mortars. These items found at Rub al Khali sites suggest an emphasis on plant processing, perhaps domestic varieties of sorghums and millets as well as cereals such as barley and wheat.