 Prior to the recent ruling by the ICZN, many invertebrate superfamily names ended in the suffix -acea, or -aceae, not -oidea as now required according to ICZN article 29.2.The suffix -oidea used to be used for some subclasses and superorders, where it is still found.In much of the older literature including Keen 1958, Moore and colleagues 1952, and the Treatise on Invertebrate Paleontology, gastropod superfamilies are written with the suffix -acea.