small stone cylinder engraved in intaglio on its surface to leave impressions when rolled on wet clay. Cylinder seals are characteristic artifacts of ancient Mesopotamian civilization and are considered some of its finest artistic achievements. The seals first appear during the Protoliterate Period (c. 3400–2900 BC), and, although the earliest examples used primarily geometric, magical, or animal patterns, later seals incorporated the owner's name and depicted a variety of motifs. Sometimes the elements were arranged in symmetrical, decorative patterns; often, however, an action was represented.