Ringicula

Helwerda, Renate A., 2015, Acteonidae, Bullinidae and Ringiculidae (Gastropoda: Heterobranchia) from the Plio-Pleistocene of the Philippines, Zootaxa 3990 (2), pp. 197-220 : 211

publication ID	https://doi.org/ 10.11646/zootaxa.3990.2.2
publication LSID	lsid:zoobank.org:pub:BDF1BC11-4848-4858-99DC-0336A5FBEE2B
DOI	https://doi.org/10.5281/zenodo.6116533
persistent identifier	https://treatment.plazi.org/id/03FA878C-951E-FE44-FF26-E4380605C9F6
treatment provided by	Plazi
scientific name	Ringicula
status

Treatment

Ringicula View in CoL spec 1

( Figure 25 View FIGURE 23 – 28. 23 )

Material. Tiep2 (1) RGM 961.753.

Characterization. Shell medium-sized; H 4.25 mm, W 3.19 mm; protoconch slightly elevated, 1.1 whorl, DP 0.27 mm; nucleus moderately small, DN 0.17 mm; teleoconch with two distinct subsutural ridges and grooves; additional sculpture of 13 irregularly spaced spiral grooves on the body whorl; lip crenulated; thin parietal callus with nearly obsolete lamella; posterior sinus rather deep.

Remarks. This specimen is rather similar in shape and size to the specimen described below under Ringicula cf. spec 1, but it differs in having two subsutural ridges and grooves instead of one ridge and groove, below which are 13 instead of 11 spiral grooves. Furthermore, its lip is crenulated instead of smooth and its posterior sinus is deeper. It is possible for a single variable species to contain such variations in sculpture and apertural characters. It is impossible to judge whether these differences are enough to treat the two specimens as separate species, because the intraspecific variation cannot be reviewed with only two specimens available. Therefore, they are not treated as separate species, even though other Ringicula species, represented in the studied material by many specimens, show very little intraspecific variation. Ringicula spec 1 and cf. spec 1 are similar in shape and sculpture to Ringicula pilula Habe, 1950 , but this species attains a larger size (H 7.0 mm, W 5.0 mm) and it does not have a subsutural ridge and groove. They are also similar to Ringicula caron Hinds, 1844 , but this species is more elongate, its sculpture of spiral grooves is more dense and it has a much stronger nodule on the parietal callus.