Granulina reginae, Elm & Hoffman, 2024

Elm, Laura-Marie Von & Hoffman, Leon, 2024, Revision of deep-water species in Granulina (Gastropoda: Granulinidae) from Mauritania and Western Sahara, European Journal of Taxonomy 925, pp. 268-291 : 277-280

Granulina reginae sp. nov.

urn:lsid:zoobank.org:act:BBBC3338-4ABA-4FEC-84CC-F5D5A2296BA6

Figs 5–6

Diagnosis

Small shell, height maximum 2.2 mm, width maximum 1.4 mm (width/height ratio 0.64), tumidity maximum 1.2 mm; ovoid shape, external and columellar lip without denticles, widely channelled and rostrated at apical and abapical ends; colour white, translucent.

Etymology

The name (feminine) of the species acknowledges the late Regina Albert , formerly a technical assistant at Senckenberg, who washed and sieved the raw Meteor samples and partly performed the preliminary sorting.

Type material

Holotype

MAURITANIA – Timiris Mound Complex • 1 shell; 18.9833° N, 16.8656° W; depth 482 m; 9 Jan. 2007; POS346 stn GeoB11587; box core in coral rubble with mud; SMF359019 .

Paratypes (12 shells)

MAURITANIA – Timiris Mound Complex • 1 shell; 18.9832° N, 16.8636° W; depth 474 m; 9 Jan. 2007; POS346 stn GeoB11588; box core in coral rubble with mud; SMF359021 • 1 shell; 18.9634° N, 16.8688° W; depth 498 m; 11 Nov. 2010; MSM16–3 stn GeoB14877; box core in coral rubble with mud; SMF359022 . – Banda Mound Complex • 3 shells; 17.6668° N, 16.6721° W; depth 440 m; 8 Jan. 2007; POS346 stn GeoB11569; box core in coral rubble with mud; SMF359023 • 1 shell; 17.6699° N, 16.6736° W; depth 505 m; 14 Nov. 2010; MSM16–3 stn GeoB14898; bottom grab in muddy silt; SMF359024 . – off Banc d’Arguin, Tanoudert Canyon • 2 shells; 20.2429° N, 17.6681° W; depth 490 m; 3 Nov. 2010; MSM16–3 stn GeoB14799; box core in coral rubble with mud; SMF359025 • 4 shells; same collection data as for preceding; RMNH.MOL.351809 .

Description

Apex with widely convex, sharp, wide channel; outer lip smooth, thickened from apex to base, protruding and somewhat bevelled at periphery, reclining towards apex and base, internally smooth (without denticles); base somewhat flared wide open. Four oblique folds at base of straight columella, folds unconnected and with rounded margins when young, upper two folds coalescent, forming vertical rim when adult. Parietal area widely convex and smooth. Macroscopic sculpture smooth with microscopic irregular growth lines; microscopic sculpture of flakes oriented towards exterior on callus of external lip, columella and columellar folds, base and apex, callus reclining in the middle part; internally smooth. Aperture curved, elongated, narrowest above periphery, wide at base and at apex. Protoconch not visible, convolved inside shell.

Remarks

All described species of Granulina from north of Senegal have labial denticles and none have a wide apical channel in the aperture. Therefore, the present species cannot be confused with Granulina nofronii , G. crassa , G. crystallina or G. cerea ( Smriglio et al. 2000) , even though they have a relatively similar form. The new species Granulina reginae sp. nov. lacks labial denticles as do the other three new species: Granulina ronaldi sp. nov., G. sigridae sp. nov. and G. sandrae sp. nov. Compared to these species, G. reginae is smaller and somewhat broad (width/height ratio 0.64), clearly more rostrated and has a wide channelized apex, which the other new species do not have. Granulina sandrae is pear-shaped and inflated (width/height ratio 0.69), and G. ronaldi and G. sigridae are more elongated (width/ height ratio 0.56–0.59).

Shells from juveniles are identified by their sharp convolving lip and four separated columellar folds; adults have a thickened, bevelled lip and the upper columellar folds are coalescent. Coalescent folds probably are a gerontic character.

Many samples containing these new species were taken in coral rubble and mud. Most likely, they live in upper bathyal coral-associated habitats. Bathymetric range is 440–505 m; their latitudinal range is 17.6– 20.3° N.

Figures

Fig. 5. Location map of the new species in Granulina Jousseaume, 1888 off Mauritania and Western Sahara. White circles show all investigated stations; colour symbols show locations of shells from new species. Granulina reginae sp. nov. is presented by yellow squares, G. sigridae sp. nov. as red diamonds, G. sandrae sp. nov. as blue triangles, and G. ronaldi sp. nov. as green circles. Bathymetric data from GEBCO; contours 500 m

Fig. 6. Granulina reginae sp. nov., Mauritania.A–D. Timiris Mound Complex.A–C. Holotype, POS346/ GeoB11587 (SMF359019). A–B. Ventral view, height 2.2 mm, width 1.4 mm, C. Micro-sculpture above second fold, see arrow in B. D. Paratype, POS346/GeoB11588 (SMF359021), ventral view, height 2.0 mm, tumidity 1.2 mm. E–J. Paratypes (SMF359025), off Banc d’Arguin, MSM16–3/GeoB14799. E–F. Ventral and side view, height 2.1 mm, width 1.3 mm, tumidity 1.1 mm. G. Micro-sculpture above second fold, see arrows in E, H. H. Columellar folds. I–J. Ventral and side view, height 2.2 mm, width 1.4 mm, tumidity 1.1 mm.