Bannerstones are ground-stone objects, usually symmetrical around a central drilled hole. Some have simple shapes, while others are more elaborate. Birdstones are similar, but they are shaped like birds, sometimes highly stylized. Bannerstones, and perhaps birdstones, might have served as atlatl weights, but the artistry suggests artistic, social, and ideological meanings as well. The photo shows a birdstone made of greenish black porphyry with gold phenocrysts. It was published by James Beer in The Wisconsin Archeologist (2014, Vol. 95, No. 1, p. 4).