Microvoluta tessellata, Ortega & Gofas, 2019

Ortega, José Rafael & Gofas, Serge, 2019, The unknown bathyal of the Canaries: new species and new records of deep-sea Mollusca, Zoosystema 41 (26), pp. 513-551 : 536

Microvoluta tessellata n. sp. ( Fig. 19 A-D)

urn:lsid:zoobank.org:act:95B5784F-1A18-47C8-9F21-2FEE7417F752

TYPE MATERIAL. — Holotype. sh., MNHN-IM-2000-34269 . Paratypes. 5 immature sh., MNHN-IM-2000-34270, all from SEAMOUNT 2 DW130 .

TYPE LOCALITY. — Off NW Gran Canaria, 28°08.95’N, 15°53.11’W / 28°09.06’N, 15°52.92’W, 655- 660 m.

ETYMOLOGY. — From the Latin tessella, a piece of mosaic, alluding to the sculpture.

DESCRIPTION

Shell whitish, consisting of 4.5 quite convex whorls, with a well marked, almost channelled suture; protoconch of one globular smooth whorl; teleoconch with oblique axial ribs of which 24 on the last whorl; spiral sculpture of rather deep grooves, rather obsolete on the first whorl and becoming more accentuated on the last whorl; grooves regularly spaced and forming granules at their intersections with the axial ribs. Aperture rather wide, somewhat arched. Three columellar folds, bulging into the aperture, occupying more that 3/4 of the apertural height, the remaining area in the adapical part of the columella somewhat concave; the adapical columellar fold is most developed and the abapical one is very slight; outer lip thin, siphonal canal short. Dimensions of holotype: 6.7 mm height × 2.8 mm diameter.

REMARKS

This species resembles in many respects Microvoluta superste s Bouchet & Warén, 1985, described from Gorringe Bank, off SW Portugal, but is less slender, more fusiform with the whorls not definitely shouldered as in M. superstes . Spiral sculpture is evenly developed over all the surface of the teleoconch, contrary to M. superstes which has smooth ribs in the median part of the whorls in most specimens. All shells are empty. A preliminary sorting of a large material from Ampère seamount, Josephine seamount and the Meteor group of seamounts collected during the SEAMOUNT 1 and SEAMOUNT 2 cruises revealed several undescribed congeneric species which are currently under study, with a differentiation between banks which may parallel that of Trituba Jousseaume, 1884 , as described by Gofas (2003). Because no animal is available, the generic placement is only tentative.

Figures

FIG. 19. — A, B, Microvoluta tessellata n. sp., holotype from DW130 (6.7 mm); C, D, paratype, same locality (4.2 mm).