Some ancient hoes, like the Egyptian mr, were pointed and strong enough to clear rocky soil and make seed drills, which is why they are called hand-ards. However, the domestication of oxen in Mesopotamia and the Indus valley civilization, perhaps as early as the 6th millennium BC, provided mankind with the draft power necessary to develop the larger, animal-drawn true ard (or scratch plough). The earliest evidence of a ploughed field in the world was found at the Indus Valley Civilization site of Kalibangan (c. 2800 B.C.).[10] Archeological finds in Prague, Czech Republic, push oldest known ploughed field even further, to 3500 - 3800 B.C.  A terracotta model of the early ards was found at Banawali, giving historians insight into the form of the tool.[11]