Cupstone

Cupstones, also called anvil stones, pitted cobbles and nutting stones, among other names, are roughly discoidal or amorphous groundstone artifacts among the most common lithic remains of Native American culture, especially in the Midwestern United States, in Early Archaic contexts. The hemispherical indentation itself is an important element of paleoart, known as a "cupule". Cup and ring marks are also common in the Fertile Crescent and India, and later in the Mediterranean, Atlantic, and Alpine regions of Europe, sometimes associated with complex petroglyphs or megalithic monuments.