Sinezona globosa, Geiger, Daniel L., 2006

Geiger, Daniel L., 2006, Eight new species of Scissurellidae and Anatomidae (Mollusca: Gastropoda: Vetigastropoda) from around the world, with discussion of two new senior synonyms, Zootaxa 1128, pp. 1-33: 16

publication ID

http://doi.org/ 10.5281/zenodo.273358

DOI

http://doi.org/10.5281/zenodo.5029676

persistent identifier

http://treatment.plazi.org/id/03B9A632-0D28-FFFA-FEB9-4E167517FA5E

treatment provided by

Plazi

scientific name

Sinezona globosa
status

new species

Sinezona globosa   new species: Figure 11 View FIGURE 11

Type material. Holotype ( MNHN). Paratype ( MNHN, 1). 415–420 m, Wallis Island, 13.350 °S, 176.133 °W.

Type locality. 310–315 m, Loyality Basin, New Caledonia, 21.533 °S, 166.483 °E.

Etymology. Globosa   , Latin adjective, noting the overall globular shape of the shell.

Description. Shell large (to 3.1 mm), trochiform globular. Protoconch of 0.875 whorls, embryonic cap with flocculant sculpture, remainder smooth with 3–4 fine spiral threads, apertural varix connected to embryonic cap, apertural margin unknown. Teleoconch I of 1.66 whorls, approximately 46–50 distinct axial cords, run over equaly spaced spiral lines, first spiral after 0.33 whorls, 14 at beginning of selenizone, interstices with broad growth marks. Teleoconch II of 1.125 whorls. Shoulder quite convex, suture modrately impressed, axials of same density as on teleoconch I, forming small points at intersection with spiral lines. Base slightly constricted below selenizone, with same density and strength of axials, approximately 20 spiral lines, becoming stronger and more closely spaced towards umbilicus. Umbilicus narrow in small specimens (paratype), moderately wide in large specimens (holotype), bordered by last spiral line of base, walls straight, smooth. Selenizone above periphery, keels elevated but often eroded due to their fragility, growth marks distinct, slit closed to elongated foramen. Aperture suborbicular, lip inflated, roof overhanging. Animal unknown.

Differential diagnosis. Sinezona macleani   new species from the Philippines is more depressed, less globular, has a protoconch with flocculant sculpture, lacks an apertural varix, has a sharp elevated keel bordering the umbilicus, and usually a projecting shelf in the basal adumbilical corner of the aperture. Sinezona plicata (Hedley, 1899)   with broad tropical Pacific distribution is overall more depressed, has a smooth protoconch occasionally with fine spiral lines, and has strong, elevated lamellae on the teleconch.

Distribution. Only known from type material.

Remarks. The paratype is slightly immature evidenced by the hardly descending aperture on the last quarter whorl, while the holotype is a fully grown specimen. It appears that the closure of the foramen occurs early on.

MNHN

Museum National d'Histoire Naturelle