Dutoitella Dingle, 1981

Brandão, Simone N., Stuhlmann, Annalena, Vital, Helenice & Brandt, Angelika, 2016, Biogeography of Abyssocythere and Dutoitella (Ostracoda), with descriptions of three new species, Zootaxa 4139 (3), pp. 391-418 : 400-402

Genus Dutoitella Dingle, 1981

Type species. Dutoitella dutoiti Dingle, 1981 (by original designation).

Additional species (listed by original binomina in alphabetical order of the species epithet) (Brandão et al. 2015; Kempf, 1986, 1988, 1994, 1995, 1996a, b, 2002, 2004, 2008a, b) Dutoitella atlantiformis Yasuhara et al., 2015 ; Dutoitella ayressi Yasuhara et al., 2015 ; Dutoitella colesi Yasuhara et al., 2015 ; Cythereis crassinodosa Guernet, 1985 ; Dutoitella cronini Yasuhara et al., 2015 ; Dutoitella dinglei Guernet et al., 2001 ; Atlanticythere eocenica Benson, 1977 ; Dutoitella lesleyae Dingle, 2003 ; Dutoitella mazziniae Yasuhara et al., 2015 ; Dutoitella mimica Dingle, 1981 ; Atlanticythere neogenica Benson, 1977 ; Dutoitella paradinglei Yasuhara et al., 2015 ; Dutoitella praesuhmi Coles & Whatley, 1989 ; Dutoitella spinaplana Mazzini, 2005 ; Dutoitella spinosa Yasuhara , et al., 2015; Cythere suhmi Brady, 1880 ; Dutoitella symmetrica Yasuhara et al., 2015 ; Dutoitella whatleyi Yasuhara et al., 2015 ; Dutoitella karanovicae sp. nov. and Dutoitella richarddinglei sp. nov.

Additional unaccepted species (previously assigned to Dutoitella , but currently accepted in other genera). (Brandão et al. 2015; Kempf 1986, 1988, 1994, 1995, 1996a, b, 2002, 2004, 2008a, b) Dutoitella hampdenensis Ayress, 1993 accepted as Taracythere hampdenensis ; Trachyleberis proterva Hornibrook, 1953 accepted as Taracythere proterva .

Dutoitella karanovicae sp. nov. ( Figures 2 , 8 , Table 1)

Diagnosis. A Dutoitella species with sub-oval lateral outline and almost smooth lateral surface (primary and secondary ornamentation strongly reduced). Subcentral tubercle conspicuous but discrete. Anterior, ventral and posterior margins evenly rounded, dorsal margin slightly sinuous.

Derivation of name. In honor of Prof. Dr Ivana Karanovic (Hanyang University, South Korea) for her outstanding contributions to ostracodology.

Material. One Subrecent (=without soft parts) adult and one “live” (=with soft parts) (A-1), four Subrecent (=empty) valves.

1) HOLOTYPE. A adult (SNB 0079): 1 originally closed carapace (right and left valves) on a micropalaeontological slide, both coated for SEM ( ZMH K- 44863).

2) PARATYPES (type locality): A “live” specimen (A-1) (SNB 0068) on two slides: valves on a micropalaeontological slide (ZMH K-44864a) and soft parts mounted in Hydromatrix permanent medium on a glass slide (ZMH K-44864b); 1 closed adult carapace (right and left valves), 1 adult right valve and 1 adult left valve on a micropalaeontological slide (ZMH K-44864c).

Stratigraphic and geographical occurrence (locality 4 in Fig. 2 and Tab. 1). Quaternary and Recent, Scotia Sea, Atlantic Sector of the Southern Ocean, 2965 to 2962m depth (only known from the type locality).

Type locality. Recent and Subrecent. ANDEEP II cruise, PS 61, ANT-XIX/4, German Research Vessel Polarstern, station 140-9, off South Sandwich Islands (off Montangu Island), Scotia Sea, Southern Ocean, 23.03.2002, epibenthic sledge trawled from 58°15.21'S, 24°52.90'W, 2965m to 58°16.29'S, 24°54.10'W, 2962m.

Description. In lateral view ( Fig. 8 .A–8.D), rounded anterior and posterior margins without prominent spines or tubercles. Straight ventral margin, dorsal outline sinuous because of small tubercles. Anterior and posterior marginal rim present, but subdued. Very small tubercles present on both anterior and posterior margins. Ventrolateral ridge oblique to the ventral margin, spines or tubercles absent. Dorsal margin is surmounted by a weak ridge on which are situated three low tubercles and a small anterior ridge. There is an indistinct, low subcentral tubercle, and a smaller, elongate, smooth node at about the anterior three-quarters length. Surface ornamentation present, but faint, weakly ornamented with fine muri, especially posteriorly. Fossae absent. Ventral surface has only the ventrolateral ridge (see above), other longitudinal ridges absent.

Internal features ( Fig. 8 .E–8.F): Outline sub-oval, anterior cardinal angle obtuse, only slightly elevated compared to posterior cardinal angle. Hinge amphidont, anterior element bi-furcated. Muscle scars poorly preserved, details not known. Zone of concrescence moderately wide, no vestibule.

Type locality. Recent. Southern Ocean, Scotia Sea, off South Sandwich Islands (off Montangu Island), German Research Vessel Polarstern, ANDEEP II cruise, PS 61, ANT-XIX/4, station 140-9, 23.03.2002, epibenthic sledge trawled from 58°15.21'S, 24°52.90'W, 2965m to 58°16.29'S, 24°54.10'W, 2962m.

A–B, E–H, holotype (ZMH K-44863, SNB 0079); C–D, paratype (ZMH K-44864a, SNB 0068). A–D, external view of right and left valves. E–H, internal view of right valve; E, entire valve; F, muscle scar pattern; G–H, anterior and posterior hinge elements.

Measurements. HOLOTYPE (ZMH K-44863), adult RV: length 1.11mm; height 0.58mm; LV length 1.11mm; height 0.64mm. PARATYPE (ZMH K-44864a), (A-1) RV: length 0.94mm; height 0.53mm; LV length 0.94mm; height 0.56mm.

Remarks. Dutoitella karanovicae sp. nov. differs from most Dutoitella species in its almost smooth valve surface (i.e., Dutoitella atlantiformis , Dutoitella ayressi , Dutoitella colesi , Dutoitella crassinodosa , Dutoitella cronini , Dutoitella dinglei , Dutoitella eocenica , Dutoitella lesleyae , Dutoitella mazziniae , Dutoitella mimica , Dutoitella neogenica , Dutoitella paradinglei , Dutoitella praesuhmi , Dutoitella richarddinglei sp. nov., Dutoitella symmetrica , Dutoitella spinaplana , Dutoitella spinosa , Dutoitella suhmi , Dutoitella whatleyi ). Although a few species (e.g., Dutoitella lesleyae , D. paradinglei , D. symmetrica ) also show reduced ornamentation, they all show more conspicuous reticulation and/or tubercles than the new species. Dutoitella lesleyae is very similar to D. karanovicae sp. nov., but they differ in the valves’ outline. The former species shows a more sinuous outline, with conspicuously protruding tubercles and nodes.

Figures

FIGURE 2. Geographical distribution of Dutoitella Dingle, 1981 in the different geological epochs or stages (for a complete list of references used for this Figure see Supplementary material 2).

FIGURE 8. Holotype and paratype of Dutoitella karanovicae sp. nov.