Talassia flexisculpta Hoffman & Freiwald 2022
- Dataset
- A review of Atlantic deep-water species in the genus Talassia (Caenogastropoda, Vanikoridae)
- Rank
- SPECIES
- Published in
- Hoffman, Leon, Freiwald, André (2022): A review of Atlantic deep-water species in the genus Talassia (Caenogastropoda, Vanikoridae). European Journal of Taxonomy 819: 140-157, DOI: 10.5852/ejt.2022.819.1785, URL: http://zoobank.org/1bed4f4b-ed7a-43cb-abc5-0173d7f93c41
Classification
- kingdom
- Animalia
- phylum
- Mollusca
- class
- Gastropoda
- order
- Littorinimorpha
- family
- Vanikoridae
- genus
- Talassia
- species
- Talassia flexisculpta
description
Description Elevated shell with rounded whorls, regular axial sculpture of raised flexuous ribs, flexuous lip and smooth protoconch, cream white. Holotype dimensions: height 2.5 mm, width 1.2 mm, apical angle 38 °. PROTOCONCH. Elevated paucispiral shell with globular nucleus and 1 ¼ whorls (Figs 45, 47, 50); first whorl smooth, last ¼ whorl with weak broad spiral bands; lip straight, slightly thickened (Fig. 50); width 0.44 mm. TELEOCONCH. Elevated spire with 3 rounded whorls and deep suture (Figs 44, 46, 49). Axial sculpture with regularly spaced flexuous ribs and numerous growth lines. Many regularly-spaced spiral lines composed of closely-aligned raised dots (Fig. 48 of paratype). Narrow, deep, elongated umbilicus at base body whorl partly covered by parietal lip (Figs 46, 49). APERTURE. Oval outline, flattened on parietal side; smooth inside (Figs 44, 46, 49). Parietal and columellar lip sharp; external lip not thickened, blunt, flexuous with notches above periphery and at base. Aperture height 1.0 mm in holotype. VARIABILITY. Sculpture of the teleoconch shows variability in strength of axial ribs. In a subadult shell (Fig. 44), the umbilical slit is nearly closed. Observed range of adult height 2.4 – 2.5 mm.
description
urn: lsid: zoobank. org: act: E 296 DB 40 - 9 DC 8 - 4 EF 4 - A 17 B-B 49046 CAA 209 Figs 44 – 50
diagnosis
Differential diagnosis Talassia dagueneti has a similar teleoconch sculpture but its whorls are more inflated, its spire is more elevated with a smaller apical angle and its protoconch has a strong spiral sculpture (Warén & Bouchet 1988; Figs 4 – 6) whereas T. flexisculpta sp. nov. has a more conical outline (Fig. 48) and a largely smooth protoconch (Figs 45, 47, 50). Talassia mexicana sp. nov. also has a similar teleoconch sculpture and a smooth protoconch; however, this species is taller and it has fine spiral cordlets on the teleoconch (Figs 22, 25, 29 – 30) which are absent in T. flexisculpta sp. nov. A comparison with other known species is given under T. laevapex sp. nov.
discussion
Remarks The radula and the soft parts of the new species are unknown; only empty shells were found in or near coral debris with silty or muddy sand. Talassia flexisculpta sp. nov. was found sympatrically with T. laevapex sp. nov.
distribution
Distribution NE Atlantic Ocean, Mauritania, latitude 17.6 – 20.3 ° N, known depth range 450 – 505 m.
etymology
Etymology The specific epithet refers to the flexuous axial sculpture.
materials_examined
Type material Holotype MAURITANIA – Arguin South 3 Canyon • 1 shell (Fig. 49); 19.7381 ° N, 17.1465 ° W; depth 483 m; 7 Nov. 2010; van Veen grab; in silty mud; MSM 16 / 3 - GeoB 14858; SMF 358970. Paratypes MAURITANIA – Arguin South 3 Canyon • 2 shells (Figs 46 – 48, 50); same collection data as for holotype; SMF 358971 • 1 shell same collection data as for holotype; SMF 358972. Other material examined MAURITANIA • 1 shell; Tanôudêrt Canyon; 20.2429 ° N, 17.6681 ° W; depth 490 m; 3 Nov. 2010; box core in coral rubble with silty mud; MSM 16 / 3 - GeoB 14799; SaM 79754 • 1 shell (Figs 44 – 45); Timiris deep coral mound chain; 18.9634 ° N, 16.8688 ° W; depth 498 m; 11 Nov. 2010; box core in coral rubble with silty mud; MSM 16 / 3 - GeoB 14877; SaM 79756 • 1 shell; Banda Mounds; 17.6794 ° N, 16.6684 ° W; depth 450 m; 8 Jan. 2007; box core in coral rubble with mud; POS 346 - GeoB 11579; SaM 79753 • 3 shells; Banda Mounds; 17.6699 ° N, 16.6736 ° W; depth 505 m; 14 Nov. 2010; bottom grab in silty mud; MSM 16 / 3 - GeoB 14898; SaM 81473.