A ding-type dish of identical shape mounded with a duck from the Brian McElney exhibition is illustrated in The Museum of East Asian Art, Inaugural Exhibition, Catalogue, pl.70, where the author notes that a sherd of a similar piece was found in a tomb dated 1057 and is recorded in Wirgin, Sung Ceramic Designs. Compare also two other shaped bowls of this type, dated to the 11th Century, a squared quatrefoil bowl with a central floral medallion illustrated in Sekai Toji Zenshu, Shogakukan Series, vol. 13, pl. 120; and a hexafoil bowl with a lotus flower-head in the Avery Brundage Collection illustrated in the Catalogue, pl. 119.

Square bowls of this shape are more commonly seen decorated in sancai glazes, such as the one illustrated as fig. 41 in EKAI TOJI ZENSHU , VOL 13, FIG. 41