Systematics / Phylogenetics
Cypraea annulus is a species of sea snail, a cowry, a marine gastropod mollusc in the family Cypraeidae, the cowries. There is one subspecies, Monetaria annulus camelorum (Rochebrune, 1884), and the parent is Monetaria (Troschel, 1863). Alternatively to the genus Cypraea, the gold ring cowry is often named to as Monertaria annulus, with the species in Monetaria often referred to as the money cowries (Meyer 2003). The four other species in Monetaria are M.obvelata, M.moneta, M. caputserpentis and M. caputdraconis. This genus diversified in the Indo-West pacific and is a sister genus to Perisserosa and Erosaria, and these three are sister to three previous genera. The earliest fossil member of these six extant complexes is Nucleolaria cowlitziana (Groves, 1994b) from the Upper Eocene.
Phylogeny of the gastropod family, Cypraeidae. Image adapted from Meyer (2003). |