The name of this genus is derived from the Greek words kallos (beautiful) and stoma (mouth), referring to the pearlyaperture of the shell. The genus Calliostoma is known in fossil records from the Upper Cretaceous onwards.[2]
The thin, acute, coeloconoid (=approaching conical shape but with concave sides) shell is imperforate or rarely umbilicate. The whorls are smooth, often polished and spirally ridged or granular. The body whorl is angulated at the periphery. The aperture is quadrangular, sinuated at the base and slightly oblique. The columella is simple, usually ending anteriorly in a slight tooth.[3] The nucleus appears to be either dextral or sinistral indifferently.[4][5]
As of 2022, Calliostoma is treated as a very broad genus of about 300 accepted species.[6] While current information is too fragmentary to assign all species in a revised genus, it is expected to be broken up and (some) subgenera will be elevated to the status of genus.[citation needed]
Distribution and habitat
The distribution of this genus is worldwide, found mainly on hard substrates, although Japanese species have been found on sandy bottoms. These snails occur from shallow waters to bathyal depths.
Contrary to what is the case in most other top shells, species of the genus Calliostoma deposits their eggs in gelatinous ribbons that are only fertilized after being deposited. The young emerge as small snails (Lebour, 1936) without passing through a free-living planktonic stage as a veliger larva.
Vilvens C. (2012) New species and new records of Seguenzioidea and Trochoidea (Gastropoda) from French Polynesia. Novapex 13(1): 1–23. [10 March 2012] page(s): 18
Williams, S.T.; K.M. Donald; H.G. Spencer; T. Nakano (March 2010). "Molecular systematics of the marine gastropod families Trochidae and Calliostomatidae (Mollusca: Superfamily Trochoidea)". Molecular Phylogenetics and Evolution. 3. 54 (3): 783–809. doi:10.1016/j.ympev.2009.11.008. PMID19919851.
Vilvens C. (2009). New species and new records of Calliostomatidae (Gastropoda: Trochoidea) from New Caledonia and Solomon Islands. Novapex 10(4): 125-163