Talassia rugosa Hoffman & Freiwald 2022, sp. nov
| Main Authors: | Hoffman, Leon, Freiwald, André |
|---|---|
| Format: | info publication-taxonomictreatment Journal |
| Terbitan: |
, 2022
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/6564593 |
Daftar Isi:
- Talassia rugosa sp. nov. urn:lsid:zoobank.org:act: F640609C-2447-4C82-9467-30AEC281163A Figs 51–56 Etymology The specific epithet refers to the rugose axial and spiral sculpture. Type material Holotype ANGOLA – Castle Mounds • 1 shell (Figs 51–54); 9.6650° S, 12.7156° E; depth 453 m; 1 Jan. 2016; van Veen grab; in fine sand with clay; M122-GeoB20958; SMF358973. Paratypes ANGOLA – Castle Mounds • 1 shell (Figs 55–56); same collection data as for holotype; SMF358974 • 2 shells; same collection data as for holotype; SMF358975 • 2 shells; same collection data as for holotype; Naturalis, Leiden, the Netherlands. Description Elevated shell with rounded whorls and flattened apex, irregular axial sculpture of raised ribs and spiral cordlets, flexuous lip and smooth protoconch, cream white. Holotype dimensions: height 3.2 mm, width 1.6 mm, apical angle 36°. PROTOCONCH. Flattened paucispiral shell with 11⁄4 whorls (Figs 52–53, 56); smooth; lip straight (Fig. 56); width 0.34 mm. TELEOCONCH. Elevated spire with 4 rounded whorls and deep suture (Figs 51, 55). Axial sculpture with irregularly spaced slightly flexuous ribs and numerous growth lines. Irregularly-spaced spiral cordlets composed of sets of closely-aligned lines of various strength; lines composed of raised dots (Fig. 54). Umbilicus nearly completely covered by columellar lip (Fig. 51, 55). APERTURE. Oval outline, slightly concave on parietal side; smooth inside (Figs 51, 55). Columellar lip sharp; external lip not thickened, blunt, flexuous with notches above periphery and at base. Aperture height 1.1 mm in holotype. VARIABILITY. Little variability observed. Observed adult height 3.0– 3.2 mm. Distribution The species is only known from the type locality. Remarks The radula and the soft parts of the new species are unknown. Differential diagnosis Talassia dagueneti has a similar teleoconch sculpture but its axial sculpture is more regular and lacks the spiral cordlets and its protoconch has a stronger spiral sculpture and a more elevated outline (Warén & Bouchet 1988; Figs 4–7) whereas T. rugosa sp. nov. has a more conical outline, an irregular sculpture with spiral cordlets and a smooth protoconch with a flattened outline. Talassia mexicana sp. nov. from the Gulf of Mexico is larger and it has a more regular and stronger axial sculpture.
- Published as part of Hoffman, Leon & Freiwald, André, 2022, A review of Atlantic deep-water species in the genus Talassia (Caenogastropoda, Vanikoridae), pp. 140-157 in European Journal of Taxonomy 819 on pages 153-154, DOI: 10.5852/ejt.2022.819.1785, http://zenodo.org/record/6564545