Talassia flexisculpta, Hoffman & Freiwald, 2022

Hoffman, Leon & Freiwald, André, 2022, A review of Atlantic deep-water species in the genus Talassia (Caenogastropoda, Vanikoridae), European Journal of Taxonomy 819, pp. 140-157 : 151-153

publication ID

https://doi.org/10.5852/ejt.2022.819.1785

publication LSID

lsid:zoobank.org:pub:1BED4F4B-ED7A-43CB-ABC5-0173D7F93C41

DOI

https://doi.org/10.5281/zenodo.6564587

persistent identifier

https://treatment.plazi.org/id/E296DB40-9DC8-4EF4-A17B-B49046CAA209

taxon LSID

lsid:zoobank.org:act:E296DB40-9DC8-4EF4-A17B-B49046CAA209

treatment provided by

Felipe

scientific name

Talassia flexisculpta
status

sp. nov.

Talassia flexisculpta sp. nov.

urn:lsid:zoobank.org:act:E296DB40-9DC8-4EF4-A17B-B49046CAA209

Figs 44–50 View Figs 44–50

Etymology

The specific epithet refers to the flexuous axial sculpture.

Type material

Holotype MAURITANIA – Arguin South 3 Canyon • 1 shell ( Fig. 49 View Figs 44–50 ); 19.7381° N, 17.1465° W; depth 483 m; 7 Nov. 2010; van Veen grab; in silty mud; MSM16/3-GeoB14858 ; SMF358970 View Materials . GoogleMaps

Paratypes MAURITANIA – Arguin South 3 Canyon • 2 shells ( Figs 46–48, 50 View Figs 44–50 ); same collection data as for holotype; SMF358971 View Materials GoogleMaps 1 shell same collection data as for holotype; SMF358972 View Materials GoogleMaps .

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; MSM16/3-GeoB14799 ; SaM79754 GoogleMaps 1 shell ( Figs 44–45 View Figs 44–50 ); 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; MSM16/3-GeoB14877 ; SaM79756 GoogleMaps 1 shell; Banda Mounds ; 17.6794° N, 16.6684° W; depth 450 m; 8 Jan. 2007; box core in coral rubble with mud; POS346-GeoB11579 ; SaM79753 GoogleMaps 3 shells; Banda Mounds ; 17.6699° N, 16.6736° W; depth 505 m; 14 Nov. 2010; bottom grab in silty mud; MSM16/3-GeoB14898 ; SaM81473 GoogleMaps .

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 1¼ whorls ( Figs 45, 47, 50 View Figs 44–50 ); first whorl smooth, last ¼ whorl with weak broad spiral bands; lip straight, slightly thickened ( Fig. 50 View Figs 44–50 ); width 0.44 mm.

TELEOCONCH. Elevated spire with 3 rounded whorls and deep suture ( Figs 44, 46, 49 View Figs 44–50 ). Axial sculpture with regularly spaced flexuous ribs and numerous growth lines. Many regularly-spaced spiral lines composed of closely-aligned raised dots ( Fig. 48 View Figs 44–50 of paratype). Narrow, deep, elongated umbilicus at base body whorl partly covered by parietal lip ( Figs 46, 49 View Figs 44–50 ).

APERTURE. Oval outline, flattened on parietal side; smooth inside ( Figs 44, 46, 49 View Figs 44–50 ). 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 View Figs 44–50 ), the umbilical slit is nearly closed. Observed range of adult height 2.4–2.5 mm.

Distribution

NE Atlantic Ocean, Mauritania, latitude 17.6– 20.3° N, known depth range 450– 505 m.

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.

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 View Figs 1–11 ) whereas T. flexisculpta sp. nov. has a more conical outline ( Fig. 48 View Figs 44–50 ) and a largely smooth protoconch ( Figs 45, 47, 50 View Figs 44–50 ). 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 View Figs 22–30 ) which are absent in T. flexisculpta sp. nov. A comparison with other known species is given under T. laevapex sp. nov.